Here is an unpopular truth: politicians are not all weak-kneed, two-faced liars

Paxman treated the three party leaders as naughty pupils who deserved a scolding

Is there an objective truth obscured by today's political leaders who are motivated above all by a desire to deceive? It is a fashionable point of view, which is why the amorphous theme of "trust" hovers over this election campaign. The holders of this view imply that there was a golden age when leaders engaged in truthful and candid debate. Now, political discourse is debased by the current government's obsession with "spin" and its almost psychopathic desire to lie.

Is there an objective truth obscured by today's political leaders who are motivated above all by a desire to deceive? It is a fashionable point of view, which is why the amorphous theme of "trust" hovers over this election campaign. The holders of this view imply that there was a golden age when leaders engaged in truthful and candid debate. Now, political discourse is debased by the current government's obsession with "spin" and its almost psychopathic desire to lie.

In relation to the war against Iraq, an alliance has formed consisting of right-wing newspapers, left-of-centre newspapers and the BBC's Today programme. It views the war through a prism marked "objective truth", working on an assumption that somewhere out there are clear and unequivocal answers in relation to the legality of the war, the use of intelligence and other matters. No matter that we are still debating the origins of the First World War.

The alliance acts for different reasons. The right-of-centre newspapers cannot forgive Tony Blair for winning elections. They would have been cheerleaders for the war if a Conservative Prime Minister had acted in a similar way. The left-of-centre newspapers opposed the war and give space to right-wing as well as left-wing columnists to denounce Blair as a liar. The Today programme works on the assumption that most politicians are hiding something big but will suddenly reveal all under relentless interrogation. It leans neither to the left nor right, but seeks what it regards as elusive "truths". Last Friday it gave up airtime to allow three writers to all argue that today's politicians lie more than ever. There was no attempt to balance or challenge these dangerous clichés.

The bias against politics climaxed with Jeremy Paxman's interviews of the three political leaders. Paxman treated each of them as naughty pupils who deserved a scolding. The interviews implied that all three political leaders were weak-kneed, mendacious bastards. That in itself is a contentious point of view even if it is widely held. Indeed, the head of television news, Roger Mosey, argued on a BBC website that surveys suggested viewers wanted tougher interviews still. Any survey in the last thousand years would have found the same. No voter is going to announce they want politicians to be given an "easier" time. The more fruitful debate is how best to challenge politicians, especially during elections when for obvious reasons the "truth" is more complicated and elusive than ever.

Politicians are not a distinctive race with a unique tendency to lie. In treating them like that we find out less and, ironically, fail to hold them to account. It becomes a game of cat and mouse, predictable theatre but nothing more. To take one example from the last election, the Today interview with Blair (when the programme was under a different editor) was dominated by allegations against the junior minister, Keith Vaz. Everyone knew Vaz was unlikely to be a minister after the election. It was a complete waste of time, but the editor thought he was being tough and clever. In reality, if the intention is always to impale a politician, he let Blair off the hook.

Similarly, I cannot remember more than a few words uttered by Jack Straw yesterday morning as he was interrogated on Today about the legality of the war. He mumbled something about UN resolution 1441 but was interrupted and told that was not the point. But for those who believe the war was legal, the UN resolution 1441 is precisely the point. For an interviewer to insist that this "was not the point" is in itself a controversial point of view.

Sir Menzies Campbell, the Liberal Democrats' foreign affairs spokesman, tells me that the weekend's apparent leak of the Attorney General's advice on the legality of the war does not move the story on. It would have been in Sir Menzies' interest to play up the leak's significance, but he has too much integrity to affect over-excitement. Sir Menzies points out that we have known for a long time that the Attorney General originally had doubts about the legality of the war, and the question posed for months has been: "Why did he change his mind?" Still we do not know the answer to this. More widely, Sir Menzies believes that the substantial question remains why Blair made an early commitment to support the war, ignoring advice from senior figures in the Foreign Office and elsewhere.

I agree with him. Having made a naively premature commitment a year before the war, Blair became trapped in a nightmare. He could not let down President Bush (and, for different reasons, Rupert Murdoch), but he needed the support of his own ministers and MPs. That is the contorted context for all that followed.

What is truth in politics? Yesterday Charles Kennedy did not give clear answers to questions about whether the world was a safer and better place without Saddam. Kennedy also has too much integrity to claim unequivocal truths.

If Thatcher had been Prime Minister in the era of rolling television news, would she have survived the humiliating origins of the Falklands War? In terms of her domestic policy, Thatcher won the 1979 election partly because of the famous poster with the slogan "Labour isn't working", implying that unemployment would fall under the Conservatives. But she knew that the short-term consequences of her polices would be a massive rise in unemployment. The poster was deliberately misleading.

In 1995 the noble Ken Clarke announced in his budget a big increase in spending on schools. But he cut the overall budget for local authorities so schools would only get an increase if all other local services were slashed. He was spinning. All hell would break loose if Gordon Brown pulled the same trick now, but in 1995 it was not the fashion to dismiss every political act as "spin".

In his column a fortnight ago, Andreas Whittam Smith cited the contrived rapprochement of Blair and Brown as an example of Blair's mendacity. But what does he expect Blair to say in an election campaign? "Look, we hate each other. We have hardly spoken to each other for the last 12 months. I occasionally fantasise about sacking him, although he is more popular than me. Vote Labour." That would be truthful, but an act of political suicide. Blair also regards Brown as a strategist of genius. Not surprisingly that is the partial "truth" he will focus on.

Between elections, politicians seek solutions to highly complex issues. They must get agreements to their preferred solutions within their parties and in an unusually hysterical media. The alternative to politicians manoeuvring and scheming would be the resolution of issues by force. I am fed up with reading and hearing all the time that politicians from Blair downwards are liars. The accusation is too simplistic. It feeds a lazy popular prejudice. More importantly, it is not true.

s.richards@independent.co.uk