As for Mr Livingstone, he is on probation

Now we will find out what Ken Livingstone is made of. As we said before the election, he faces a choice between using the mayoralty as a platform for opposition to Tony Blair, or as a springboard to enhance London's reputation as a vibrant world city.

During his long campaign, he showed extraordinary political skill, running rings round the Prime Minister, himself a consummate politician. If those talents could be turned to serve the capital, if his internationalism could make London a great European city, the verdict of the people would be vindicated.

Mr Livingstone has made, it must be said, a worrying start. The moment the BBC broadcast its exit poll, he was on to criticise Tony Blair for his meanness to pensioners and calling on him to "unite the Labour Party", a depressing piece of 1981-vintage cant. And when he started quoting his old columns for this newspaper on the effect of the high pound on Ford at Dagenham, worry turned to alarm.

On the other hand, Mr Livingstone's coalition-building rhetoric, promising an administration that reaches out across party lines, promises the kind of pluralism that Mr Blair once seemed to offer.

It is not only Mr Livingstone whose political maturity will be tested in his administration. The Green Party's winning three seats on the Greater London Assembly is of great symbolic significance, although the actual policies advocated by Mr Livingstone's possible deputy mayor, Darren Johnson, are a rather unstable mixture. If the Greens can give a radical edge to a transport policy which puts trains and bicycles ahead of cars and lorries, fine. If they encourage Mr Livingstone to indulge in naive anti-capitalist and anti-car posturing, however, they will betray the important cause of practical environmentalism.

In his previous life as leader of the GLC, 1981-86, one of his strengths was in appointing people who had imaginative solutions to the city's problems. He brought in not just cheap fares but a simpler zoned system, welcomed by natives and visitors alike. If he can shake off the trade unions, and the largely irrelevant obsession with the financing of the Tube which is not anyway the mayor's responsibility, and concentrate on what really matters, namely appointing the right people to manage the system, he might finally prove Margaret Thatcher wrong to have abolished the GLC.