Can the Tories exploit this crisis of confidence?

This Government cannot be trusted to tell the truth. Or at least that is the damning conclusion of the latest NOP poll for Channel 4's Powerhouse programme, to which 78 per cent of all respondents said that they could not trust this Government. And on sleaze the figures are almost as bad ­ 64 per cent said that Labour is no better than the previous Conservative government.

Even worse is the view among Labour voters, of whom 70 per cent say the Government is dishonest. While the war of words between Downing Street and the press over the man in tights with the black rod has left most voters bemused, the issue has reinforced a lasting impression be of a government that has forfeited the trust of the electorate. Previous governments in this position ­ notably under Macmillan, Wilson, and Major ­ never recovered.

The electorate has often taken the view that politicians are, by nature, prone to be economical with the truth, but what makes these latest poll figures so significant is that the voters once thought that Mr Blair's lot were genuinely different. He will therefore pay an even heavier price because he staked the whole basis of his appeal on political clean living. All those phrases ­ "I'm a pretty straight kind of guy... purer than pure... whiter than white" ­ now have a pretty hollow ring and are coming back to torment the Prime Minister.

Meanwhile, the bodies of more than 40 former ministers whose careers have been terminated by dismissal through a succession of reshuffles are piling up. The leap-frogging of a few bright young sprogs to junior appointments last month has signalled to the remaining Labour MPs from the 1997 intake that their prospects for promotion are effectively over. Ambition and expectation have given way to resentment and bitterness ­ a lethal cocktail.

When a government is no longer trusted, the headline opinion polls are sure to follow. Already there has been constant and steady erosion of support for Labour and the lead over the Tories has shrunk to single figures. On the basis of the meltdown and panic that has so far occurred, Heaven knows what mayhem will set in should the main parties reach level pegging. At such a point, over 100 Labour MPs will be fighting for their survival in three years.

No wonder Gordon Brown ­ how strangely silent he has been these past three weeks ­ has taking to writing billets-doux to sacked ministers while keeping backbenchers supplied with invites to soirées at Number 11. He must know that Mr Blair is past the halfway mark of his premiership. And so, in turn, does his rival, David Blunkett, as he tries to make the best of his climb-down over his proposed "snoopers' charter".

While the smart money may still be on the Prime Minister to lead his party into the next election, bookies have slashed the odds on his bowing out this side of polling day. Mr Blair is simply incapable, as Margaret Thatcher was capable, of coping with unpopularity. The crowds in the Mall booed him when his image appeared on the giant screens during the Jubilee pop concert. He will get the same treatment in the pubs if he tries to muscle in on the World Cup, should England reach the final.

Meanwhile, the threats of Tory defections that greeted Iain Duncan Smith's election have evaporated. Indeed, the traffic may be about to go the other way. That bellwether of political opportunism, Ivan Massow, who defected to the still rolling Labour bandwagon amid a hail of hugs and kisses from Mo Mowlam two years ago, told John Humphrys on the BBC yesterday that his Labour membership had now lapsed. "I just wanted to teach the Tories a lesson." he said, implying that he might yet be about to worm his way back.

But more important clues are around, as even Portillista Tories wonder whether it isn't time to place an each-way bet on Mr Duncan Smith. I was struck by a well directed question from Archie Norman to Mr Blair last week, exposing a broken Labour promise to make free prescriptions available to sufferers of cystic fibrosis. Sir Archie, perfectly reasonably, likes to be on the winning side. Did I detect the first signs of a rapprochement with the Tory frontbench? Certainly their deputy chief whip was at pains to point out to me how very helpful Mr Norman had been. Only Francis Maude still seems to be sulking in his tent, making absurd claims that unless the first six Tory candidates selected for the next election include women they won't have changed. Yes they do need more women, but this is a ridiculous, arbitrary benchmark by which to make a final judgement.

Meanwhile, Mainstream Conservatives, the umbrella group of Europhiles and supporters of Ken Clarke have studiously behaved themselves. While the skirmish surrounding Dominic Cummings's advice to Mr Duncan Smith to show restraint during a euro referendum campaign annoyed members of the backbench 1922 committee, a general sense of discipline has succeeded in ending the remaining skirmishes left over from last year's civil war.

This is not the time for Tories to publish long policy tracts. But if they can establish the charge of incompetence on issues such as blunderer Blunkett's "snoopers' charter" to sit alongside dishonesty, they are halfway to seeing off Mr Blair ­ perhaps before polling day.

mrbrown@pimlico.freeserve.co.uk