A question of what might have been for candidate who turned down Tories

It could so easily have been Ken versus Brian rather than Ken versus Boris. Brian Paddick, the Liberal Democrat candidate, was wooed by the Tories to be their standard bearer in the mayoral election before they chose Boris Johnson.

Mr Paddick, a former senior Metropolitan Police officer, sent David Cameron an email asking if speculation that the Tories wanted him to be their man was true. The Tory leader quickly dispatched Francis Maude, a Shadow Cabinet member, for talks."They promised me the Earth, all the money I could spend and professional back-up," said Mr Paddick.

He turned the Tories down after discussing their offer with his mother, who said her own mother would have been appalled. "It was a question of principle," he said, "Which is maybe why I will find it difficult to win this election. I am not prepared to stand up and say things I don't believe in. A lot of people have said 'you are a fantastic candidate, why are you running for the Lib Dems?' That is who I am. I am a Liberal Democrat."

But there is just a hint he is thinking of what might have been. "I think if I had stood for the Conservatives it would have been 'Brian and Ken' rather than 'Ken and Boris'," he said.

The Liberal Democrats were delighted to win the tug-of-love for Mr Paddick and had high hopes, but his campaign has not taken off. Mr Paddick has looked a grey bystander as the media focuses on the colourful battle between Ken Livingstone and Mr Johnson. Although he trails a poor third in the opinion polls, Mr Paddick still hopes for a last-minute surge ahead of Thursday's election.

Under the supplementary vote system, Londoners are allowed to cast a first and second preference vote. If no candidate gets more than 50 per cent of the first preferences, the top two go into a run-off and the second preference votes of those who put other candidates first are added.

Mr Paddick conceded that he is many people's second choice –but knows that would not get him into the second round."There are a huge number of voters who cannot stand the thought of another term of Ken Livingstone and a huge number who can't stand the thought of Boris Johnson as Mayor," he said. "As a consequence they – wrongly – believe they have to vote first preference for the other man. Second preference votes are all going to come to me.

"Faced with a ballot paper, it will come home to them that Ken Livingstone has been there too long, Boris Johnson is too much of a risk and they will vote for me. I don't think it's over until it's over."

The second choices of Mr Paddick's supporters are widely expected to decide the Ken versus Boris battle. But he is resisting pressure from the two leading candidates to give his backers a nod in their direction.

It has been a frustrating political baptism for the former police officer. At hustings meetings, he has sometimes struggled to get a word in. If he interrupts, he is accused of rudeness. "You have to be grown up about it. The Ken Livingstone-Boris Johnson Punch and Judy Show is entertaining and is more likely to boost circulation than somebody who talks common sense, has the experience and track record of delivery. That's life," he said.

But has he enjoyed it? He is commendably frank: "People used to ask me that about my police career and I'd say 'now and again'."

He has no intention of becoming a Liberal Democrat MP but doesn't entirely rule out another foray into politics when he has recovered from this gruelling campaign. "I did the London Marathon two weeks ago and vowed never, ever to do it again. At the moment I am thinking why would I ever want to do this again. But never say never."

The man and his manifesto

Age 50 (last Thursday)

Experience Former Deputy Assistant Commissioner of the Metropolitan Police

USP The gay cop

Key policies Pledge to cut crime by 5 per cent a year. If it were not reduced by 20 per cent at the end of his first four-year term, he would quit. Would focus on getting knives and guns off the streets. Would also chair Metropolitan Police Authority. Cross-river tram route; action to refurbish London's 83,000 empty homes as sustainable homes at affordable rents; all major new developments to be self-sustaining in energy, waste and water consumption

Campaign Struggled to muscle in to battle between Ken Livingstone and Boris Johnson

Strengths Offered reassurance to Londoners on their number one issue – crime. Would bring real-world experience to job

Weaknesses Seen as having little to say apart from on crime.