Ken Livingstone, the incumbent Mayor of London, has rejected the methodology of an opinion poll company used by Stonewall, the Evening Standard and other papers.
The latest poll of 1,000 Londoners from YouGov puts his Tory rival Boris Johnson on 49% with the Mayor on 36%.
Lib Dem candidate Brian Paddick remains on 10% and Green party hopeful Sian Berry on 2% in the Standard poll.
Once the second preferences are factored in, Boris leads Ken by 56% to 44%.
London voters will choose a Mayor and 25-member London Assembly on May 1st.
The Ken Livingstone’s campaign team has called the polling company’s methodology “fundamentally flawed” and said it will complain.
YouGov has been criticised because it only uses online polls, which not all of the population have access to, and because people are paid or offered competition prizes to take part.
“YouGov’s internet polls on the London Mayor election are totally out of line with polls using established methods; this is because You Gov’s methodology is fundamentally flawed,” said the Livingstone campaign.
“In their previous London poll, for example, although the Office of National Statistics estimates 26% of Londoners to be aged 55-plus, YouGov’s weighted data gave 39% in this age group.
“YouGov do not take account of the much larger ethnic minority population in London.
“These and other mistakes mean that they consistently over-estimate support for the Conservatives in London compared to established polling techniques and, as last week, we clearly reject this poll.
“YouGov’s polls are misleading the public and we have therefore decided to make a formal complaint about their basic flaws to the Market Research Council of Great Britain.”
On its website, YouGov defends the use of internet-only surveys:
“The internet … has spread to every significant demographic group, with 62% of GB adults logging on.
“Online researchers are able to reach sufficient numbers of women as well as men, over-60s as well as under 30s, people on below-average as well as above-average incomes.
“National surveys are therefore conducted to represent the public as a whole.”
YouGov’s president, Peter Kellner, said today:
“We’re not to proud to go back and check the ONS data and today’s poll does contain the new figures.
“They’re trying to divert attention away from the fact that they have a real problem.
“Our results are consistently finding that one in five people who are, broadly speaking, Labour will vote for Johnson.
“I will wait and see whether the MRS contacts us and I will be very interested to see which particular rule or code of conduct we are supposed to have breached.”
The company was recently used by gay equality organisation Stonewall to compile a wide-ranging report into perceptions of discrimination among the gay, lesbian and bisexual community.
Serves You Right, released last week by Stonewall, used a YouGov online interview administered to members of the company’s Great Britain panel of more than 115,000 individuals who have agreed to take part in surveys.
1,658 lesbian, gay and bisexual adults took part between 6th and 10th December 2007.
Ken Livingstone, Boris Johnson, Brian Paddick, Ms Berry and Respect – The Left list candidate Lindsey German will all speak and answer questions at a Stonewall hustings event at BFI Southbank on Saturday 19th April.
PinkNews.co.uk is proud to be Stonewall’s media partner for the hustings, which will be held at the between 11am and 12.30pm.
The event is open to everyone, but in order to ensure a seat you must register here.
Full list of candidates for Mayor of London:
British National Party
UK Independence Party
Christian Peoples Alliance and Christian Party
The Left List
The Stonewall hustings will be the last before Londoners go to the polls on May 1st.