Still a consummate politician, but Ken trails 'joker' Boris

He came, he chatted, he bent a pipe. The London mayoral race entered its final week with Ken Livingstone trailing Boris Johnson, as the Labour candidate struggled to get out of second gear.

His arrival, on foot and in pouring rain, at Southwark College last week was part of a campaign to charm the youth vote. Unfortunately, Livingstone's performance was high on deliberation but low on charm.

Oona King, unveiled as his "young people's champion", tried her best before dozens of young people, crammed into a college cafeteria. Livingstone detailed the policies that might win his audience over – the educational maintenance support, reduced transport fares, increased housing, but he failed to convince anyone that he really wants to win.

He entertained only five questions – three of them from a student who confessed he was a Liberal Democrat. When a college official proudly announced he had worked for Livingstone at the Greater London Council 30 years ago and that "He [Livingstone] is London", he was rewarded with little more than a bashful smile.

On a brisk ramble to the workshops, it was Ed Balls who led the way, asking most of the questions – and making most of the jokes. The man who is London, who has led the European Union's biggest city for most of his political life and hopes to lead it again, was happy to play the shadow chancellor's straight man.

Until, that is, he saw the pipe-bender. Manipulating a length of copper into a J-shape turned out to be the most fun Ken had all morning. "I'm glad the whips didn't have any of these when I was in Parliament," Livingstone mused, eying the industrial-sized contraption before him. "Come here. Stick yer arm in there. Heh, heh."

The exertion showed that, while Livingstone is fighting his fourth mayoral campaign, he is not jaded. Yet the man formerly known as "Red Ken", appears detached from the people he aspires to lead. His party confesses that Labour supporters will have to "hold their noses" and vote for Livingstone – whose ratings trail Labour's by several points – if they want to get rid of Johnson.

Livingstone bemoans media attacks and a lack of "serious reporting", but concedes a problem with Johnson's cross-party appeal. "Every day on the streets, 25 to 30 people stop me and say 'You've got to win'," he said. "I suspect with Boris people say 'Tell us a joke'.

"Do you want a comedian to make you laugh or someone who can cut your fares and build some homes and get you back to work?"

He remains a consummate politician, whether mounting a soap-box in the rain outside the Treasury to make an off-the-cuff attack on government cuts, or going for the jugular when asked why Polish voters should support him. "They should remember very few politicians stood up and supported Solidarity in those great struggles when Poland was trying to break free of the iron curtain," Livingstone told Polish Radio. "I was one of very few politicians to stand up and support them right down the line."

He blames Johnson's performance for "forcing" him to stand again. "If Boris Johnson had done the job, I wouldn't have stood. I'd have said 'That's great; he might be a Tory but he's doing the job'.

"But he isn't doing the job. I'm doing it because he isn't."

As his entourage entered Bermondsey Tube station, a voice announced to startled commuters: "Sack Boris; Vote Ken!"

If Johnson is re-elected mayor, that announcer may be looking for a new job come Friday evening; if Livingstone wins, he might just find himself in charge of Transport for London.