The Prime Minister must be judged on his record of deception and lies

People with no regard for the truth are very dangerous. Robert Maxwell was. So is Tony Blair

This election will turn on one thing, and one thing only. Do enough people see that the Mr Blair, the Prime Minister, is essentially a con-man. He communicates well, but as often as not what he says is untrue, or intended to deceive. I shall give six cases. Peter Oborne, in his book The Rise of Political Lying, published today, gives further examples. New evidence is coming to light all the time.

This election will turn on one thing, and one thing only. Do enough people see that the Mr Blair, the Prime Minister, is essentially a con-man. He communicates well, but as often as not what he says is untrue, or intended to deceive. I shall give six cases. Peter Oborne, in his book The Rise of Political Lying, published today, gives further examples. New evidence is coming to light all the time.

Take the Labour Party political broadcast which will be shown tonight. Shot by the distinguished film-maker Anthony Minghella, it apparently displays Mr Blair and Mr Brown as a harmonious team doing their best for Britain. But unless everything that every political correspondent has written about the relationship between the two men has been consistently wrong, this advertisement would also be a sort of fraud on the public. Like the Iraq dossier.

Truthfulness was not an issue which dogged Mr Major or even Lady Thatcher. Some people may have disliked the latter's policies and deplored her sentiments, but they didn't accuse her of deceit. Nor did they make such a charge against Lord Callaghan or Edward Heath. One would have to go back more than 80 years to Lloyd George to find a prime minister as distrusted as Mr Blair.

By what standard should prime ministers be be judged? One way of describing the test was given by Lord Butler when he was Cabinet Secretary. In evidence to the Scott enquiry into the sale of arms, he said: "You have to be selective with the facts ... it does not follow that you mislead people. You just do not give the full information ... it is not justified to mislead." In effect, Lord Butler was making a distinction between not telling the whole truth and untruths.

Exhibit One. When the suicide of Dr David Kelly, the British arms inspector, was announced, Mr Blair was asked by journalists whether he had authorised the leaking of the scientist's name. The Prime Minister: "Emphatically not. I did not authorise the leaking of the name of David Kelly." However, Lord Hutton's subsequent enquiry into the events leading up to Dr Kelly's death shows that Mr Blair chaired a series of meetings at which it was decided to release the fact that an official with the Ministry of Defence had admitted contact with the BBC journalist Andrew Gilligan.

Exhibit Two. During the recent debate on the Prevention of Terrorism Bill, the Prime Minister told MPs that to accept the amendment on the so-called "sunset clause" "would be contrary to the strong advice given to us by our security services and our police". But when Lord Falconer, the Lord Chancellor, was later asked about the matter in the House of Lords, he admitted that MI5 had not told the Government that the country would be at risk if there were a sunset clause.

Exhibit Three. The recent Labour poster unveiled by Mr Blair that proclaimed: "Warning: the Tories will cut £35bn from public services". Mr Blair's team said that this was equivalent to sacking every doctor, nurse and teacher in the country. But of course the Conservative Party has no such plans. It expects merely to expand public expenditure by £35bn less than Labour over a long time period of time.

These examples are the small change of political discourse. Yet the pattern is the same with the big-ticket items.

Exhibit Four. The dossier on Iraq's weapons of mass destruction was solemnly presented to the British people as the intelligence services' considered view. However, the wording of the assessment had been changed as a result of pressure by Downing Street staff. Inevitably the meaning was altered. In particular, the country was allowed to draw the erroneous conclusion that British bases in Cyprus were at risk from long-range weapons of mass destruction that could be deployed in 45 minutes.

Exhibit Five. When making the case for the invasion of Iraq in the House of Commons, the Prime Minister made selective use of the intelligence he had received, and thus misled Parliament. Mr Blair did not inform members that the Joint Intelligence Committee had recently warned that "there was no intelligence that Iraq had provided chemical or biological materials to al-Qa'ida or of Iraqi intentions to conduct chemical or biological attacks using Iraqi intelligence officers or their agents."

Exhibit Six. I put this last example forward more tentatively, because it is drawn from Robert Peston's book Brown's Britain, rather than from an official statement or report. However, it fits the pattern. Mr Peston describes the Treasury's work on the tests for British entry into the euro. He quotes a colleague of Mr Brown as saying of the Prime Minister: "He could not conceive that we (the Treasury) had not prejudged the outcome."

Mr Peston writes that the notion that the Treasury was producing an impartial and objective assessment was anathema to Mr. Blair. In describing the Prime Minister's role, Mr Peston emphasises Mr Blair's desire "to fix the outcome of the tests to allow the UK to join the euro". But the Treasury would not bend.

These examples demonstrate that the Prime Minister does not distinguish between what, in his opinion, ought to be the case and the actual facts. The "what ought" always takes precedence over the "what is". Thus no prime minister should have had anything to do with the naming of Dr David Kelly, so Mr Blair said he had not. The security services ought to have deplored the presence of a sunset clause in the Prevention of Terrorism Bill, so he said that they had done so. The wicked Tories always slash public expenditure, so Mr Blair said that was what they were proposing. Saddam Hussein must have weapons of mass destruction, so any suggestions to the contrary have to be wrong. Britain should enter the euro, so the Treasury's tests must show that it is right to do so. In each of these examples, the Prime Minister breaks Lord Butler's rule: "It is not justified to mislead."

It may seem exaggerated and unfair to compare in this regard the Prime Minister with the late Robert Maxwell, the former Labour MP and business tycoon who looted the pension fund of Mirror Newspapers. But there is a connection. I knew Mr Maxwell over a number of years, first when I was a financial journalist and then when he became an unwelcome shareholder in this newspaper. It took me a long time to realise that in conversation he stated only what was useful to him regardless of whether it was true or false. This caused him no uneasiness. If you caught him out in a lie, he swiftly smoothed away the discrepancy and carried on as before.

In a similar way, I believe that Mr Blair habitually states what ought to be the case, regardless of whether it is strictly true or false. He feels completely justified in doing so. Like Mr Maxwell, he is unembarrassed when found out and carries on regardless. People with no regard for the truth are very dangerous. Mr Maxwell was. So is the Prime Minister.