Andreas Whittam Smith: Tony Blair has presided over a deceitful government. He must be voted out of office

If people cannot believe their government, then no progress is possible. That is why the questions of trust repeatedly raised during these weeks leading up to the general election are so important. It would be a waste of time, for instance, asking oneself whether policy for the National Health Service was sensible if hospital managers, consultants, doctors, nurses and support staff came to assume that ministers could not be relied upon to tell the truth. They would simply stop being frank with government departments and fudge their performance indicators and engage in charade.

Without trust, nothing can be done, not in health, not in education, not in the prevention of crime, not in managing the economy, not anywhere. A party manifesto is literally a waste of paper if the authors are believed to be deceitful.

A white paper is published, say, on a subject of concern: can we read it as a fair analysis or do we assume that relevant material has been omitted for political reasons? A new Bill is proposed in Parliament that affects one's interests: would we find that the legislation was being rushed through so as to avoid proper scrutiny?

New security restrictions affecting our daily lives are announced: can we assume the threat is real, or must we wonder if the changes are primarily designed to get us into a particular frame of mind?

As we prepare to go to the polls tomorrow, therefore, we must first confront the issue of character before we turn to questions of policy and competence. Is a government led by Tony Blair a dishonest enterprise? That is the bleak question we must face.

If it seems shocking, as it is, to ask this of any British administration, remember how many large commercial businesses we once assumed were respectable have recently proved to be fraudulent when we have finally been able to see their inner workings.

In the case in front of us, however, charges of dishonesty have been directed solely at the Prime Minister because he holds himself out as taking all the decision other than those falling to the Chancellor of the Exchequer, Gordon Brown.

Let us start, then, with Mr Blair. In the past few weeks, there have been ample opportunities to compare some of the public statements he has made during the past two or three years with what we have now learnt was going on at the time. Senior officials must have leaked these secret documents as a form of whistle blowing. There were fresh revelations over the weekend. One gets the impression that the supply is inexhaustible.

Taking the examples made available to us as a whole, I don't see how anybody could deny that they demonstrate a pattern of deception. The Prime Minister habitually states what ought to be the case regardless of whether the facts fit. In Mr Blair's mind, the "what ought" always overwhelms the "what is"; he operates on the principle that saying something makes it true.

And because this seems to be instinctive in the Prime Minister, it is best seen as a condition. Mr Blair isn't in a position to say to himself: "Oh dear, I have been found out, I won't do that again." If he is re-elected, he won't be able to stop doing it again, and again, and again.

However, one has to go further. If one judges the prime minister of the day to have been persistently deceitful, then one must ask oneself whether the stain has touched the rest of the Cabinet. As a matter of fact, I know of no example where a dishonest boss has worked for years with honest colleagues. Life isn't like that.

If the charges against the Prime Minister are well founded, as I believe they are, then the best that can be said for ministers is that they have been dupes. And indeed the fact that none of them demanded a cabinet paper setting out the Attorney General's full advice on the legality of the war in Iraq confirms that impression.

Confronted with this and acknowledging the truth of it, some Labour supporters advise the use of the clothes peg. Hold your noses and vote Labour. After all, the deception hasn't been venal. Nobody in government has been engaged in financial corruption. There has been no money in it for anybody. Deception has been necessary for maintaining support for Labour's vital reforms.

As the right-wing press lies about Labour, so this argument goes, Labour is entitled to use the same weapon. In other words, natural Labour voters must put up with the deceit because the purpose is good.

One has only to state this line of reasoning to recognise it for what it is. For it makes the familiar but always terrible mistake of confusing the means with the ends, the type of error that has brought misery to millions of people through the centuries. I know of nothing more dangerous, nothing more frightening.

I voted Labour in 1997 and 2001 and I would vote Labour again. But not while Mr Blair is leader. There is no room here for judicious consideration. Voting for a party led by Mr Blair is out of the question

What to do instead? There is a sensible course of action but there is also an idealistic, romantic response. The first would be the most efficacious in expelling Mr Blair from power. In Labour held constituencies one would vote for the party which came second last time, whether it is Conservative or Liberal Democrat.

This might produce a hung Parliament and the immediate bundling of Mr Blair out of office. Good. It might let in Mr Howard as leader of a Conservative administration with a narrow majority. This would be better than a continuation of Mr Blair, though far from perfect in my opinion. Apart from what one might think about Mr Howard's attitude to immigration, he was a member of a government led by Mr Major which was charged with misleading Parliament by the Scott inquiry.

Hence the all-or-nothing tactic which I favour. Vote Liberal Democrat in every constituency. Treat the general election as if it were a giant, nationwide by-election. Make your vote a protest vote. Remember the numerous occasions on which the Liberal Democrat candidate has scored a completely unexpected triumph with a massive swing.

Don't worry about the Lib Dems' unfamiliarity with government, either in a coalition or, mirabile dictu, on their own. That, funnily enough, was true of Labour in 1997. Normally one votes for something. This time one should be primarily concerned to vote a dishonest government out of power.