Bruce Anderson: Tories should have no cause for despair: 'Time for a Change' is still a winning slogan

Yet this should not unduly depress Tory spirits. The corollary is also true. If there were an economic downturn, it would be hard for any government to survive. In an era of post-tribal politics and shallow party allegiances, voters will be less and less ready to listen to excuses, even if they are good ones. Like new owners taking over a failing firm, their first instinct will be to fire the existing management. If the economy were in trouble, it would take an opposition leader of the calibre of Neil Kinnock - or David Davis - to lose an election.

Moreover, the economy will not be the only issue. "Time for a change" has always been the most potent slogan in British politics. By the next election, it will be in many voters' minds, even if Gordon Brown has replaced Mr Blair. It is true that the Tories appeared to rejuvenate themselves by disposing of Mrs Thatcher, but John Major benefited from the curiosity aroused by an unknown figure. That would not apply to Mr Brown. He has been so centrally associated with this government that to uncommitted voters, it would not seem that much of a change.

Admittedly, Gordon Brown might have some success in winning back disillusioned Labour voters; whatever his policies, his body language is to the left of Tony Blair's. But what about middle England, the political territory which obsesses Mr Blair? On a platform, Mr Brown is formidable. He is also charmless and even menacing, as Mr Blair is well aware.

The PM's regular bouts of reluctance to hand over to the Chancellor are not just caused by his own desire to stay in No 10 and his doubts as to whether Gordon could be entrusted with the Blairite legacy. Mr Blair is also not convinced that Mr Brown would be good at winning elections.

That has not been a recent Tory forte. But the Tories did go into the last contest with two disadvantages. The first was Michael Howard. Mr Howard is one of the most admirable men in public life. He is utterly straight and he is excellent company. That view of him is shared by almost everyone who knows him, but by hardly anyone who has only met him through the media. The latter outnumber the former.

At the last election, when I encountered Tories who were not enamoured with Michael Howard, I would say: "If he was the man you think he is, he would not be married to Sandra Howard." Perhaps the Tories should have used that as a poster; it would have captured the public's attention. Hardly anyone voted Tory because of Michael Howard and he may have cost the party a couple of per cent.

So did the absence of an economic policy. At the last election, the Tories had less to say about the economy than any major party in any modern campaign. That is like trying to play rugger without a scrum. Assuming that the next Tory leader is halfway competent, this mistake will not be repeated.

On the economy, as Angela Merkel must now know, John Howard of Australia was right. You cannot fatten the pig on market day. It is no use springing new economic ideas on the voters once the election has started. You have to make your case two or three years earlier.

As prominent Tories will discover this week, many ordinary party members are frustrated that this has not already started. They see a set of ministers who grow more arrogant, incompetent and mendacious by the day, while the Tories are doing and saying nothing. The exasperation is understandable, but the worries are overstated.

When a government is decisively re-elected, it does not matter what the opposition does in the first months of a parliament. It can allow itself the luxury of sorting out its own affairs, provided it does so in the right way. Equally, it hardly matters that the Tories are not yet in a position to assail the government, when it is so effective at self-laceration.

The footage of Mr Wolfgang being thrown out of the Labour conference was worth a million Tory press releases, as was the lick spittle police reaction: using anti-terrorist legislation to deny him re-entry. This all confirms a widespread public belief that the Blair lot are getting too big for their jackboots, and that they are corrupting public servants into accomplices.

Over the summer, it has also been revealed that the former transport secretary, Stephen Byers, lied to the Commons over Railtrack, while David Blunkett lied to just about everyone else. To exploit that properly, the opposition needs Parliament: one reason why Mr Blair is happy to keep it in recess. It seems an age ago that the Commons was last sitting. But it will be back next week. Mr Byers' malfeasance will be high on the agenda.

The Tories are hoping to push their attack beyond Mr Byers. Having recovered from the disappointment of an unsuccessful leadership campaign, Alan Duncan, the shadow Transport Secretary, spent much of the summer establishing a case not only against Mr Byers, but also against Mr Brown. From the evidence it is clear that long before Stephen Byers lied, no one in the Treasury trusted him. To be fair, it was his competence which they derided, not his honesty, but the Treasury did not allow Mr Byers to choose between tea and coffee without asking for permission.

If the Transport Secretary had no power, the Treasury must take responsibility. Holding Stephen Byers to account for Railtrack is like launching legal proceedings against a glove puppet. The Tories intend to place the blame where it belongs, with the puppet master.

Of itself, Mr Byers' admission that he lied will not entitle the Railtrack shareholders to compensation. But it weakens the government's case. Even by recent standards, the Railtrack affair was spectacular for its clumsiness, bullying and lying. Ministers treated an important company and its stockholders as if they were a dissident pensioner in the conference hall. They may find that Railtrack too can retaliate, and that the process of apology will be protracted, cumbersome and costly.

Railtrack will still be running long after the Tory leadership contest is over. In order to exploit it and other opportunities, the Tories will need a strong, articulate, able and attractive leader; someone who can emulate the wisest Tories throughout history, and adapt old principles to new circumstances. It is my belief that by the time David Cameron finishes his speech on Tuesday, he will have convinced a lot of Tories that they have found the leader they need.