Boris Johnson is better liked than Ken Livingstone and has been more successful in delivering his key campaign messages but this may not be enough to convince voters to make him mayor of London on May 1.

A focus group organised by Populus on behalf of The Times found that Mr Johnson was likely to be overhauled by Mr Livingstone when voters turn their attention to the race in earnest.

Of the ten Londoners selected to provide a cross-section of the capital’s voters, three were leaning initially towards Mr Johnson, three to Mr Livingstone, one was thinking of voting Green, one for the Liberal Democrats, and two were undecided. After 90 minutes of debate, support for Mr Livingstone had risen to five, Mr Johnson’s backing had dropped to two, Brian Paddick, the Liberal Democrat candidate had one likely voter and two were unsure.

Mr Johnson, standing for the Tories, can take comfort that the group was drawn from inner-London boroughs . The Times will be repeating the exercise later this week with voters in outer London – the main target of the Conservatives’ campaign.

Lynton Crosby, the veteran Australian political consultant running Mr Johnson’s campaign, will be pleased to learn that his candidate has succeeded in explaining his key policies to inner-London voters.

The group quickly identified crime, the £25 congestion charge and buses when asked to list the Conservatives’ priorities. Asked for their negative impressions of the Johnson campaign, none could recall a gaffe by Mr Johnson – not an outcome many would have predicted at the start of his bid.

Nor will a last-minute Labour effort to scare potential Johnson voters from the candidate be effective, the opinion research suggests. Presented with a “nightmare scenario” such as a repeat of the 7/7 bombings the group was not unduly troubled about the prospect of Mr Johnson at the helm. “It’s irrel-evant. Procedures are in place,” said one member of the group. “It’s the people that matter,” said another. For the Liberal Democrats the results are less ambiguous. There was an ominously long silence after the group was asked to name the party’s candidate before one asked if “Hugh Paddick” was running for mayor. Brian Paddick was at least identified as a Londoner, along with Mr Livingstone. Several members said that Mr Johnson – who was born in New York and went to Eton – was not a Londoner.

There was disagreement over whether this mattered. “It would help to be a Londoner. Ken has experience. It helps to be in tune with people,” said one.

Were the race a popularity contest Mr Johnson would be a clear winner, the focus group suggested. While Mr Livingstone was associated with vanity and arrogance, his main rival was viewed as “refreshing” and “honest and quirky”. However another member said of Mr Livingstone: “I kind of like his arrogance. He’s a very strong character and that’s a good thing.”

Another pointer is that there is little evidence that national politics are having much of an impact. The group agreed that both candidates stood outside the battle between Gordon Brown and David Cameron. “Brian Paddick doesn’t stand out from the Lib Dems. Ken Livingstone and Boris Johnson stand out from theirs,” said one member. There was general agreement that the Prime Minister would be a liability for Mr Livingstone.

The explanation for the group’s tilt towards the Labour candidate may be because it was the first time most had concentrated on the race. Mr Livingstone, judged initially to be arrogant, was in the course of the session credited with improving transport, lowering crime and being a “good ambassador for London”. None of the group brought up any of the allegations of corruption that dogged the early part of his campaign.

Andrew Cooper, co-founder of Populus, said: “There is no evidence from this that there is a ‘time for a change’ mood in London as there may be nationally. People are bored with Livingstone and find him increasingly unlikable. Nor are they perturbed by the idea of a Boris mayor. It’s just that this seems to be a pretty marginal call and it’s almost as if Livingstone has done a better job of persuading people he wants it more.”

Mr Johnson will be hoping that he has better luck in stirring up the suburbs.

Two politicians go into a bar . . .

— Ken Livingstone walks into a pub. He is wearing a suit and is surrounded by his all-male entourage. He orders a pint of bitter but does not chat. Boris Johnson walks into a pub. He is wearing casual clothes and is one of group of men and women. He orders a gin and tonic and talks freely.

— Pollsters use techniques like this to draw out people’s deeper opinions about politicians. This exercise, in which the focus group was asked to envisage the candidates out drinking, suggested that voters think Mr Livingstone more formal than his rival.

— In another exercise, members were asked to depict their visions of London under the candidates. Brian Paddick, a former policeman, may be dismayed to learn that one thought he would preside over a “police state”. Ken Livingstone, above, appeared as a smiley face.

Times Recommends

• The bright side of this winter rain
• Story behind the picture: Snow Leopard, 2008
• Times Charity Appeal: The Place2Be