No money, no staff, no chance – but independent mayoral candidate Siobhan Benita is getting London excited

She is making waves in the mayoral race. Oliver Wright meets her

It was an odd, but apt, place to launch a political campaign. Sandwiched between stalls for the Royal Navy and Avon at a careers fair for east London sixth-formers, Siobhan Benita could hardly make her voice heard above the din.

Behind her a small projector screen displayed her picture under the simple slogan: "Siobhan for Mayor". In front: just a few television cameras and journalists, and a lot of bemused teenagers, most of them too young to vote. But if Ms Benita's London mayoral launch was a little amateurish, just being there was an achievement.

Last October, she left her job as a civil servant in the Department of Health to embark on a new "career" as an independent candidate in this year's election. She had no money, no staff, no party and, frankly, no hope against the political juggernauts of Ken Livingstone and Boris Johnson.

Today, six months on, her chances of winning may still be tiny but her campaign is generating excitement.

Her odds of success on 3 May have fallen from 500/1 to 50/1 and she stands a decent chance of pushing the Liberal Democrat candidate Brian Paddick into a humiliating fourth or even fifth slot. His odds of winning are now 100/1.

Ms Benita, 40, now has a support staff of 20 full-time volunteers, and is getting noticed and written about by the political commentariat. In the ultimate accolade some are even beginning to attack her.

The journalist Simon Jenkins described her this week as "a political upstart who has not even run for her local council". But he still dedicated most of his column to her candidacy.

All this has been done against the backdrop of almost no television exposure – the key way of getting your name and message out to voters.

Despite giving Mr Livingstone equal billing with the other main party candidates when he stood as an independent candidate in 2000 they have all but ignored Ms Benita.

She has been excluded from the Newsnight mayoral debate, and unless the broadcasters have a change of heart she will be missing from next week's Question Time, and other debates on ITV and Sky. It clearly rankles. "The BBC are steadfastly applying out-of-date rules to this election," she says. "They are applying rules that were created for a General Election to an election which is all about an individual. Their criteria are how well your party did at the last election and that is ridiculous.

"I'm an independent. I don't have a political party. I'm saying there are seven candidates in this election and from the moment we are official they should give us more coverage."

The odd thing about Ms Benita is that for an insurgent candidate her background, demeanour and policies are rather too conventional. A married mother of two from New Malden in south-west London, she joined the Civil Service in 1996, working her way up through the bureaucracy of Government with stints in the Department of Transport and the Cabinet Office to become head of corporate management in the Department of Health.

Her candidacy is backed by that arch establishment figure, the former Cabinet Secretary Sir Gus O'Donnell, and her policies pledges are generally anodyne to the extent that they would not be out of place in Blairite manifesto. Her leaflets promise "to work for every child to have an excellent primary school place" (even though education is not in the remit of the Mayor), "support long-term investment to keep London's economy strong" and "put more police on the streets".

Controversially perhaps she supports building a third runway at Heathrow – but so did new Labour.

Despite entering politics only six months ago, she also has the "politician's patter" down as well as the other candidates. In her opening remarks yesterday her pitch was as a "fresh, modern, alternative".

"The great thing for me is the fact that we are now getting so much momentum behind my campaign," she gushed. "When people know that I am here and when they hear about my campaign they really, really like it.

"People are very disillusioned by party politicians at the moment and I am reminding them this is the one opportunity they get to not vote for a political party. I can feel from the attention that we're getting that people are really behind us."

After she said the focus on the personalities of Ken and Boris meant little attention had been paid to what each candidate would do in the role if elected. "It's a ridiculous, macho, Punch and Judy show going on between Ken and Boris. They have hardly talked policy. They have hardly got policies. And that's not right. That's not right for London."

But in many ways Ms Benita is selling herself on personality as well, and that is why she has been successful.

She hopes, in particular, to attract women voters put off by the main candidates and to that end will be answering questions on Mumsnet, the parenting website, later this week.

Regardless of exposure the odds are still stacked against her. So the question arises: what next after 3 May? Will she attempt to capitalise on her new found exposure to join a political party with the back-up to help her win elections in the future?

She may say she's not like the other mayoral candidates but she still falls back on the old politician's trick of not really answering the question: "I have loved every moment of this campaign and I have met so many fantastic people across London who don't usually get listened to," she says. "Someone needs to give them a voice so I'm not stopping."