On Wednesday, David Cameron, the leader of the Opposition, repeated his charge that a "thread of dishonesty" runs through Mr Brown's leadership. Yet dishonesty has always been part of the warp and weft of politics. More than 2,000 years ago, Plato observed that it will be for the rulers of the city "to use falsehood in dealing with the citizenry or enemy for the good of the state". "No one else must do so", he added.
Even if you accept this notion that the state may, so to speak, lie for our benefit, which I don't, the philospher's injunction has provided an excuse for generations of political leaders and their officials to plead reason of state for every species of chicanery imaginable.
During John Major's administration, for instance, the Scott Inquiry into the supply of British arms to Iraq revealed a secretive government, riddled with incompetence, slippery with the truth and willing to mislead Parliament. Government ministers at the time claimed that all that was done was done "in the public interest".
It was done to save their skins, as Tony Blair's observation, unearthed by Peter Oborne, in his book The Rise of Political Lying, makes plain. In 1987 Mr Blair said: "The truth becomes almost impossible to communicate because total frankness, relayed in the shorthand of the mass media, becomes simply a weapon in the hands of opponents." In other words, you daren't tell the truth because it will be used against you. This won't do either. Lance Price's account of working for Mr. Blair in Downing Street (The Spin Doctor's Diary) shows where this analysis leads. He recounts that he had only been in the job five days when the question of the legal problems of the former Leader of Westminster Council, Lady Porter, came up. "No concern in No 10", he was instructed to say to media inquirers, and adds: "Perhaps my first exercise in less than 100 per cent veracity."
Three months later Mr Price records that Gerhard Schroder, the German Chancellor, had snubbed New Labour. The Prime Minister had personally invited him to come to the Labour Party Conference. But he's gone to Paris instead, Mr Price wrote in his diary that evening, "so we lied and said we hadn't invited him".
The question is whether dishonesty is becoming more than just a thread and is now colouring the entire fabric of British political life. A scene comes to my mind. It is Mr Blair's triumphant arrival in Downing Street on the morrow of his first election victory. Excited crowds are waving flags. What popular joy!
Except, as we learnt later, these weren't ordinary people at all. They were party workers brought in especially for the purpose of scene setting. It was a deception, mild indeed, but nonetheless designed to mislead television viewers. That has been the pattern ever since.
The Government's habit of double counting its achievements is a good example. Referring to one of Jack Straw's announcements as Home Secretary, a fellow Labour MP remarked: "Jack Straw has been in a bit of trouble over seeming to claim that we were providing 5,000 extra police officers when all we're actually doing is stabilising police numbers".
The same Jack Straw confessed to over-claiming parliamentary expenses to cover council tax for four years. By applying for a 50 per cent "zero occupancy" discount the bill for his constituency home in Blackburn and claiming the full amount on expenses, Mr Straw received more than £1,500 to which he was not entitled.
This is the thread of dishonesty: bogus police numbers, bogus expenses claims followed, as we shall see, by bogus contrition. For even the letters that Labour MPs started writing to party workers to apologise for the parliamentary expenses scandals were a deception. "I thought twice about sending this letter because I know how rightly angry people are." From the heart! Except that party headquarters had drafted the letters. Labour MPs had only to fill in the recipient's name and add their signature.
Why does deceit come so easily to quite a few members of Parliament, to numerous party professionals and, it must be added, to some civil servants, too? Because in their hearts, I believe, they are contemptuous of ordinary people.
New Labour once held a "Listening to Old People" event in London. Ministers came to speak. But no questions were allowed. "Ministers are busy people", the audience was told, "we should all be grateful that they found time to grace us with their presence." Your role and mine, then? To be stage-managed and deceived as necessary.