The man frequently described as Britain's most influential political journalist is ascribed powers to dictate government policy and make or break parliamentary careers. Les Hinton, executive chairman of News International, owners of The Sun, says: "The mention of his name stirs a response in every politician - rarely one of warmth but always one of respect."
Kavanagh, who is said to have a direct line to his ultimate boss Rupert Murdoch, has spent nearly 23 years in the House of Commons but will next month move upwards to become an associate editor of the tabloid. That does not mean he will end his quest for political scoops, of which he has had an inordinate number.
His exclusive stories have ranged from Princess Diana getting divorced, and giving up her HRH status, to Tony Blair planning to hold a referendum on the euro. He also revealed the date of the last general election well ahead of the pack.
But his personal favourite exclusive is nothing like so grand and even sounds modest. He decided to go ahead with a Sun splash predicting, the day after the 1987 general election, that Norman Tebbit planned to step down from the Cabinet. The story was not one of his best sourced. Kavanagh was taking a hint, reading between the lines and allowing his instinct and his judgement full rein. When asked by Kelvin MacKenzie if he was sure about the story, Kavanagh replied that he was as sure as he could be.
"I had enough of an instinct to jump, but it really was a leap in the dark. I worried about it all night," Kavanagh admits.
The next day The Sun's political editor was being ribbed about the story by rivals as they all sailed up the Thames at Windsor on a day out. This time, they suggested, Kavanagh, who was biting his nails, had taken too much of a flier.
And then they turned on a transistor radio aboard the boat for the 1 o'clock news. The lead story said that Norman Tebbit had just announced that he was standing down from the Cabinet.
Kavanagh is prepared to admit that he too can sometimes get things wrong, although he says the sub-editors on The Sun have caught most of his worst howlers. "The number of times I have woken up at 2am and thought: I didn't write that, did I?," he says. "I had but the subs had very sensibly removed it so when I picked up the paper in the morning I'd have this tremendous sense of relief."
There was one recently that did get through. He managed to get Shias and Sunnis mixed up in a story about the Iraq war.
"By some ghastly mistake in the process of typing I got two of the most crucial elements of the crisis in the Middle East the wrong way round. You cannot afford to make mistakes like that," admits Kavanagh ruefully as he sits in a quiet corner of the RAC club.
While everyone makes mistakes it is some of Kavanagh's quite deliberate efforts that have caused the greatest controversy.
"Nightmare on Kinnock Street", which may have helped to end the prime ministerial ambitions of former Labour leader Neil Kinnock, was one of Kavanagh's efforts. The raw material for the MacKenzie-inspired diatribe had been supplied by Conservative Party advisers.
More recently when Labour agriculture minister Nick Brown was outed as a homosexual, Kavanagh was the man behind a Sun splash that demanded: "Tell us the truth Tony: Are we being run by a gay mafia?"
The Sun political editor went on to the Today programme to deny that the paper was adopting a homophobic stance. There was a danger that gay ministers would work together on issues such as the age of consent and the pubic had a right to know their sexuality.
Colleagues and rivals in the parliamentary lobby are clearly fond of Kavanagh, although not all of them admire all of his stories equally. Michael White, political editor of The Guardian who is also moving upstairs and becoming an assistant editor of his paper, chooses his words carefully when asked to describe Kavanagh's achievement.
"Trevor has been an extraordinary success as the respectable face of Rupert Murdoch's tabloid empire. When he is on television or Radio 4 he sounds like an avuncular professor of politics at a respectable university, a great achievement in itself. Fortunately for him the TV interviewers do not read everything he writes," says White with great precision.
Last year Kavanagh attracted yet more awards, envy and admiration when he revealed the entire contents of Lord Hutton's report on the BBC 24 hours before it was published.
Rumours have persisted that a copy may have leaked, not from the Government, but from a printing source and obtained by a Sun reporter but that Kavanagh was detailed to write it.
Asked about the rumour Kavanagh gives the sort of dissembling answer that he would never accept from a government minister. "There is an enormous amount of speculation about this story and I don't intend to add to it at all," Kavanagh replies.
But the allegation is that you accepted awards for what was only partially your work. "It was my story," he says emphatically.
You wrote the story? "It was my story," insists Kavanagh.
That's all you are going to say about it? "Mmm," he says.
There will probably be fewer exclusives in future as he moves over to the gentler life of associate editor.
"I have been doing this job for very nearly 23 years and it's been a long and fantastic roller coaster ride and I've enjoyed every minute of it. But going out and getting good stories isn't a thing that goes with age. I think it's a young man's game," says Kavanagh, who is 62.
In the new year he will return to his office in the Commons but will concentrate on commentary, features and a weekly political column. "It's a bit too late in my career to start something completely different. It's what I know best. If I am a round peg in a round hole then the round hole is the House of Commons," he admits. Before too long he could also soon be one of those advising on whether The Sun, which is increasingly critical of many aspects of Tony Blair's Government, should support David Cameron's Conservatives.
Cameron may be the best Conservative around at the moment but Kavanagh believes that there is a long way to go before The Sun could back him as the next Prime Minister of the UK.
"He is an utterly untried and untested person and we have got to see if there is steel, whether he is prepared to take difficult and tough decisions," says Kavanagh.
In the end Rupert Murdoch will decide whether or not The Sun and Kavanagh backs Cameron and the decision will be taken on the basis of a hard-nosed assessment of whether or not the new Leader of the Opposition has a realistic chance of winning.
No one asked to imagine a Sun journalist would ever come up with a figure like the tall, slim, distinguished-looking Kavanagh who looks after "the serious bits" in the paper and who admits he has never been a member of the foot-in-the-door school of journalism. "When we do something we do it big and we do it in a way that has impact," he says. "An exclusive story on the front page of The Sun, or an opinion piece which begins to move events in any way, wouldn't have the same impact in another of the national newspapers. We just have this enormous clout."
A key turning point in his career came when Walter Terry, The Sun's political editor, become the victim of one of Kelvin MacKenzie's many sackings. Despite being only number three on the paper's industrial desk, Kavanagh was suddenly catapulted by MacKenzie into the top political job on the paper without knowing anything of the geography of the Palace of Westminster or even who to phone.
Kavanagh suggests that Terry is one of those who has a greater claim to lasting industry recognition than he has because he was "one of the greats - one of the people who have really moved events."
Kavanagh, the son of a Dublin-born upholsterer, who never even considered the possibility of going to university, has had more than his fair share of stories that have moved events.
"We have got some very big stories across the range. The interesting thing is that when The Sun lands on the opposition's desks, people do pick up the paper these days - if it's in The Sun it must be right," says Kavanagh. If The Sun's credibility has improved, then a lot of the credit must go to its political editor.
Some might sneer but Kavanagh's reputation within the newspaper industry is great. On the inaugural list of journalists for the Newspaper Hall of Fame announced last month, there was only one political editor among the 40 names.
Kavanagh says: "I was astonished to be on the list at all and delighted obviously as well. You can't help but be incredibly proud about being ranked alongside the likes of Hugh Cudlipp and Larry Lamb. These are the giants of the industry."
The man who has been called Rupert Murdoch's hatchet man added: "I was really chuffed. To have your picture hanging in the National Portrait Gallery, even briefly, is wonderful."
Kavanagh is best known as something of a cheerleader for the government of Margaret Thatcher, although he insists he has never been a member of a political party nor has any firm or fixed ideological commitments. Instead, his beliefs, formed initially by a Labour-leaning family background in Reigate, have been shaped by a number of experiences during his working life. Two spells working in Australia where he first met Rupert Murdoch, and his wife Jacky, then an air hostess and a beauty queen, were very influential.
Before working in Sydney and later Canberra as a political reporter, Kavanagh, who emigrated to Australia on what he calls a "£10 Pom ticket", worked in the New South Wales town of Tamworth. "I discovered there was no class structure. It was my first experience of a classless society. You could go into a bar and you find yourself standing next to two guys in shorts and thongs and they'd be the mayor and the local prosecutor."
Coming back to the UK in 1978 during the Winter of Discontent further concentrated his mind, as did the 1986 Wapping dispute when Murdoch took on the print unions and won.
"The position is frankly you can't do this job unless you share at least some of the views of the paper itself. You've got to be going with the grain and the grain was pretty easy for me to go with because I felt that what Margaret Thatcher and the Conservative Party were trying to achieve in those days was absolutely the right thing to do," Kavanagh says.
His political beliefs could easily be summed up as an attachment to small government, lower taxes and strong defence, combined with a suspicion of the bureaucratic nature of the European Union. The Sun, he explains, has consistently opposed British involvement in a single European currency and its precursors because of the loss of economic sovereignty involved. He adds that the UK is in a process "of managed decline" within the EU.
"I think that one day the European Union will disintegrate under its own contradictions. It may not happen for many years to come. It isn't a matter of pulling out. I think it is a matter of the whole thing falling apart," insists Kavanagh.
He is clearly seriously disillusioned by the record of New Labour even though the paper was able to support a lot of things the Government did in its first eight years, such as sticking to its borrowing plans and not raising income tax. Kavanagh believes that Tony Blair had the power, goodwill and momentum to do a few things really well, such as sort out the health service or modernise the transport system. It hasn't happened.
"In the first term they didn't tackle anything. Their only object was to win a second term," says Kavanagh, who asked the Prime Minister in the 2001 election campaign whether he would have done things differently if he had known how well his popularity would hold up.
"He said he had to spend the first term learning to drive - you had to find out where the clutch and the brakes are. Well, I don't think a government should be allowed to believe it has a rehearsal term," says Kavanagh. "At the end of eight years what have you got? A lot of things left undone - that's the thing I feel." And while he believes that Sir Bernard Ingham, Margaret Thatcher's press secretary, was "as straight as a gun barrel", the New Labour approach was to deny the truth whenever possible. "Labour knows that to use the word 'spin' doesn't quite cover some of the tactics they used and they know they have got themselves a terrible reputation which they still haven't fully recovered, if they have recovered at all," he concludes.
He holds former press secretary Alastair Campbell and Tony Blair himself responsible for the disintegration of trust. Yet he concedes that although Campbell is both ruthless and brutal, this is balanced by integrity, courage and sense of humour.
One thing is certain: as he begins to observe David Cameron in his new life as columnist, his views and his judgements will be well known to Rupert Murdoch. While the jibe that he was Murdoch's hatchet man was made in Australia a long time ago, the two men do talk and Kavanagh's views are trusted.
It was a trust built up over time. "Everything for me has been incremental. I start off doing a story and then another story and then another. Stories come and stories go but somewhere gradually I guess I was building up some sort of credit rating," he says.
The relationship with Murdoch is more than reciprocated. The chairman of News Corporation, he says, is not only a businessman with a triple A rating but one who has never been given sufficient credit in the UK for his achievements.
"He is a guy who has created huge numbers of jobs in this wonderful industry. We would not have as many newspapers today if it wasn't for Wapping," says Kavanagh, who went to work on the Surrey Mirror only after the chief constable of Surrey had turned him down for a job as a policeman.
What will the future hold now for Trevor Kavanagh? He is certain only that he does not want to be like Lord Deedes, writing in his 90s. "Frankly I feel I have done pretty well. I am not aiming for anything but then I never have particularly," he says.Reuse content