Londoners must not "wash their hands" of their responsibility to resist the coalition's austerity measures, a senior Labour MP has said.
Writing on The Huffington Post on Monday, John Trickett, the shadow minister for the Cabinet Office, said that rather than beng a "mere buffoon" Boris Johnson was "at the centre of the most dangerous group within an already dangerous Conservative Party".
"We can't let the Tories get away with it. A second term for a Tory Mayor will have consequences for us all," he said.
"On Friday Mr Clegg encountered mothers who are going without meals in order to feed their children. He said you would have to have a cold heart not to be affected as if their plight had nothing to do with the government of which he is the deputy prime minister."
"But the voters must not think, like Clegg, that they can wash their hands of responsibility for their actions on Thursday if they fail to vote against the Tories.
"Let every elector in London understand that their actions on Thursday can either accelerate the austerity or contribute to the resistance."
Defending Trickett's comments on the BBC's Daily Politics programme on Monday afternoon, Labour MP Jonathon Ashworth said his colleague was merely reminding voters that "Labour oriented people should vote for a Labour candidate".
"What John is saying, in a very direct way, is Boris Johnson is a big celebrity, but people who vote for Johnson [should remember] they are voting for a Tory," he said.
Trickett and Ashworth's comments display concern in the Labour Party that Ken Livingstone is a drag on their party's ticket.
A YouGov survey for the Evening Standard published today, Johnson a four-point lead of 52%-48%, after second preferences were taken into account.
However the poll did show indications of a drop in the so-called "Livingstone drag" effect, which has made Labour's candidate less popular than his party in London polls.
Only 9% of those planning to vote Labour in the London Assembly elections said they would back Johnson in the mayoral ballot - compared to 13% two weeks ago.