I’m sure Boris Johnson isn’t attending Labour’s Spring Conference, but his ears must be burning red.

His name was taken in vain by two government ministers in set-piece speeches ahead of the big turn by Ken Livingstone, who rarely misses an opportunity to disparage his rival for the London mayorship and did not disappoint an appreciative audience.

Yes, the Ken and Boris show has arrived in Birmingham but is missing half the act.

Boris will not welcome Communities Secretary Hazel Blears’ description of him as a “nasty, right-wing elitist, with odious views and criminal friends like Conrad Black.”

And he would certainly disagree that his election on May 1 would be a “disaster for London”, as Livingstone put it.

But he will take comfort from so much conference time being devoted to rubbishing his candidacy.

It shows that despite the rhetoric, Labour takes his challenge very seriously.

Olympics Minister Tessa Jowell admitted as much when she told delegates to close their eyes and imagine they were waking up to Johnson elected as Mayor of London.

“Don’t laugh,” she told the party members. “The mayoral race this time is closer than it’s been at any point since Labour gave London back its government eight years ago.”

Livingstone, a master of the political putdown, said Johnson had repositioned himself as “Ken Lite” who would keep the Congestion Zone but cut it to half its size.

“Government in London is incredibly serious business,” said Livingstone. “It’s not simply a photo opportunity, nor an appearance on have I Got News For You.”

Boris must be loving all the attention.