Ministers who once regarded Livingstone as a liability now depend on him for success

He is the electoral shield behind which Labour hopes to hide in the days that follow next week's election results

Here is a prediction. After this month's elections a senior minister will pop up on the BBC's Today programme and proclaim a triumph for Labour even if his party has lost bucket loads of votes.

Here is a prediction. After this month's elections a senior minister will pop up on the BBC's Today programme and proclaim a triumph for Labour even if his party has lost bucket loads of votes.

Probably the minister will be John Reid. The Secretary of State for Health's remit includes coming to the Government's rescue, telling John Humphrys that what appears to be a political disaster is really a great victory: " First of all good morning, John. Of course John, we did not do especially well in parts of the country. No one can be surprised at that. But we won in London. That's quite an achievement, to win in the capital ... you have to accept that, John. London voted Labour, John".

It is one of the great political ironies of our times. Ministers are keeping their fingers crossed that Ken Livingstone can do it for them in London. He is the electoral shield behind which they hope to hide in the days that follow. Around much of the country they will get a hammering. Perhaps London will buck the trend. Not so long ago the finger-crossing ministers were the vote winners who regarded Livingstone as an electoral liability. Now they hope to cite a Livingstone victory as proof that they are still in the game.

New Labour's nervy pioneers must be confused. After all they have fought a war. In Britain military conflicts are usually popular. In contrast Livingstone has openly introduced a charge on motorists in a land where taxes are supposed to be a vote loser and the car driver is king. Yet it is Livingstone not the Government who is popular.

Livingstone launches his campaign for re-election today having made his mark in London. In particular the introduction of the congestion charge was an act of genuine political courage. Some leaders like to proclaim their boldness as if the proclamation in itself makes them bold. Livingstone just got on with it. In advance of its introduction the opinion polls suggested the charge was deeply unpopular. In such a daunting political context I suspect that a fully paid-up New Labour Mayor would have introduced an experimental scheme on a single road in Lambeth, to be implemented at two in the morning for an hour or two. Ministers would have hailed this move as a historic initiative, citing the charge as an example of their radicalism while pointing to its experimental nature to prove they were still the motorists' friend.

Instead the congestion charge is a practical example of an astute soundbite delivered many years ago by Paddy Ashdown when he was leader of the Liberal Democrats: "There should be no taxation without explanation." Everyone realised it was almost impossible to travel in London with its clogged roads and creaking underground. Soon after the introduction of the charge a significant section of London's population recognised that the roads were quieter, while those who continued to drive paid a tax earmarked for improving public transport.

These are political decisions that make a direct and recognisable impact, much more so than tentative policy reviews and experimental initiatives. The political strength of the charge is that some doubters have been converted by experience, in the same way Margaret Thatcher swayed voters by specific policies such as the sale of council houses. Those who have been swayed include the more innovative thinkers in Government. They regard the congestion charge as one of the most significant and radical policies introduced since 1997, pointing the way to other revenue raising measures.

There are lessons to be learnt from this for political leaders across the spectrum. Livingstone had the self-confidence to challenge the prevailing prejudices in the media and elsewhere rather than constantly seek to appease them. Sometimes it is the newspapers, rather than political leaders, that are forced to reconsider their stance. In the early 1980s the London Evening Standard was relentlessly hostile to Livingstone when he was leader of the GLC. To the editor's alarm some of his readers approved of the lower tube fares and the rest of Livingstone's eclectic package. In order to retain these readers the Standard toned down its onslaught.

Something similar has happened this time around. The newspaper's attacks on Livingstone in his early years as Mayor have been replaced most of the time with a more reflective tone, still critical but less strident. Sometimes political leaders are in a position to tame the mighty newspapers rather than dance to their tunes.

Livingstone is a laid-back tamer, another lesson for some of those political performers who splutter impotently. In Livingstone's case it is his opponents who become apoplectic in their fury. Neil Kinnock rages at the mention of Livingstone. The normally jovial Frank Dobson is reduced to a fuming silence when the Mayor's name is raised. John Prescott could hardly bare to raise his hand in support of Livingstone's re-entry to the Labour Party. Four years ago New Labour's control freaks, at the height of their powers, could not control him. They pressed all their buttons with an increasingly manic fury and Livingstone calmly strode on to victory.

Moving to the political right, I will never forget a television programme called Meet the Press where a panel of journalists interviewed Livingstone in 1982, shortly after he had met the Sinn Fein leader, Gerry Adams. One of the panelists was Paul Johnson. Johnson began the programme with an unusually florid complexion, but half way through his face reddened to the point at which it looked as if it had caught fire. Livingstone was unfazed and got the better of the exchanges, appearing far more reasonable than his apoplectic interrogator. There is something to be said about remaining politically calm through storms, letting others lose themselves in fearful rage.

We will never know whether this brand of determined but pragmatic progressive politics would have flourished on a national stage. Perhaps the pressures are so great and complex in government they require a more timid pragmatism. Even on the smaller canvas of London Livingstone's most distinctive policy will inevitably lose him some votes. Steve Norris, the Conservatives' formidable candidate, is opposed to the congestion charge and will pick up the support of those who are enraged by it. Yet when I interviewed Norris at the weekend for GMTV's Sunday Programme the point he sought to highlight on several occasions was this: "Ken is not standing as an independent. He is Tony Blair's candidate, the Labour candidate." Not surprisingly one of the points Livingstone will make at today's launch is that he is very much his own man, opposed to the war from the beginning.

While ministers cling to him like a political lifeline his opponents seek to damn him by association. For now at least new Labour needs Livingstone much more than he needs new Labour. "Please stop interrupting, John. You keep on saying our vote collapsed around the country when our candidate, Ken, won in London ... it's been a good night for Tony Blair and the Government, John."

s.richards@independent.co.uk