I assumed the candidature would be determined by which of us could draw the sword out of the stone

It already seems like a year ago. When I look back in my diary, it seems that the struggle to be Labour's candidate for mayor of London has completely taken over my life. The one real exception was when I got an invite to the Vogue millennium party - their concession to the sartorially challenged. Vogue's latest edition is celebrating the millennium with a photo-shoot of all the people they would have to their ideal party. They've got some wonderful pictures of me chatting to Lord Snowdon. But no, I am not running for mayor on a joint ticket with him.

I realised I needed a break: I'd been doing three or four speeches a day. Nine months ago, I had been approached by the University of New York to deliver a lecture on democratic participation in local government. On the not unreasonable assumption that the Labour Party would have selected its candidate by now, I agreed, only to have to phone the organisers and cancel the event when Labour's selection committee decided to hold its interviews on Tuesday, 16 November. We decided to have a break in Brighton - just as good as spending all that money shopping in New York.

In the end, it was not as much of a break as I had hoped, because Saturday's papers announced that Labour's selection panel would clear me to seek the nomination. I had an early-morning call from Radio 4's Jim Naughtie and, recognising the irresistible force of history, came back on Sunday.

After a day of catching up with paperwork, I took part in a Carlton TV debate on policing. All the candidates were discussing their policies on crime. All, that is, except Frank Dobson. He did not even send his lovely deputy Trevor, which led the Evening Standard to call him "the invisible candidate".

Tuesday is the big day, of course. Even though the press have all been briefed that I will be allowed to stand once I've gone before the scrutiny panel, I still find I am incredibly nervous. I am the last candidate on and fight my way through the scrum of camera crews outside Millbank Tower. The only thing journalists want is a picture of me standing next to the Ken Livingstone supporter who is wearing an umbrella on his head. The very polite American intern escorts me to the waiting-room and plies me with biscuits. When I am finally ushered into the star chamber, its green hue creates the impression of being at the bottom of an aquarium, apart from the vast portrait of Clem Attlee hanging on the wall. The committee has obviously decided that loyalty oaths are a bit medieval for new Labour in a new millennium, which is rather disappointing, as I had assumed that after the oath, the candidature would be determined by which of us could draw the sword out of the stone to produce the once and future mayor.

My ten-minute presentation seemed to be well received, but the committee then got bogged down in a nit-picking debate about hypotheticals. Ian McCartney led the charge, demanding that I should sign up in advance to the manifesto, irrespective of what it might contain. My protestations that we haven't actually got a manifesto yet were brushed aside. After 20 minutes of going around in circles, Clive Soley decided to move on to other matters and after that things went like a dream.

As Glenda and I shuffled around the television studios to respond to the verdict, we became increasingly alarmed at the delay to the announcement. We'd been promised a decision at 5.30pm, but by 7pm, when we rushed off to address a meeting for all the Labour candidates called by the three Tube unions, we hadn't received word of any decision. In Frank's absence, it was left to Glenda to explain the government's plans to transfer chunks of the Tube to Railtrack.

Then a moment of high drama: I was passed a written message that the jury had suddenly been sent home for the night without making a decision. Minutes later came the news that I am to be summoned back to explain my position.

That evening's Newsnight was electric. I have never seen Glenda so angry as she made it clear what she thought of the vetting panel - even though Jeremy Paxman pointed out to her that by criticising Labour's selection process she was committing a breach of Labour Party rules. By this time, I was so tense that when Paxman asked if I had a question to put to Clive Soley I couldn't think of one. By the time I got home, it was 11.30, but the Mirror and the Evening Standard were waiting on the doorstep to have a last word. Just as I was about to go to sleep, the phone rang. It was ITN wanting to know if I could be in their studio at 5.10 the next morning (expletive deleted).

By the time you read this, you will know the outcome of my return visit to Millbank Tower. If selected as Labour's candidate for London mayor, I will stand on the manifesto agreed by the Labour Party. I would not withdraw if selected.

But the party has not yet agreed its London manifesto and in the selection I will exercise my right to argue for what should be in the manifesto. At the end of the process, the party will have a clear picture of the views of the London party, Londoners and the mayoral candidate. On that basis, a manifesto will then be drafted.

The Labour Party stands for devolution of power to the people and democratic control of local government. I remain passionately committed to those principles.

Ken Livingstone is the former Mayor of London.