Ken Livingstone and the lab rats

Ken Livingstone, campaigning to hold on to his job as Mayor of London in the face of a concerted effort from his Tory opponent Boris Johnson, has a blast from the past to contend with: two former colleagues have been talking about the years Ken spent in his twenties working as a laboratory technician in south London, carrying out procedures on live animals.

Just to make things sound doubly sinister, Ken worked in the lab's 'X block'. He was responsible for injecting rodents and sheep with cancer cells. The animals were were either given experimental treatments to fight the cancer, or observed to see how their immune systems coped.

Dr Chris Grant, who was researching his doctorate at the Chester Beatty research centre when the young Livingstone worked for him, and is now based in California, told the Sunday Times that he remembered Ken as a "confident animal technician" who enjoyed his job. "He would be responsible for setting up the cages, putting the right amount of mice in there and injecting them with the right amount of whatever I gave him."

And what about the young man's politics? Grant's brother Roger, who worked at the lab at the same time, said: "Many times he would start a discussion on his social ideology and you would say, 'No, Ken, you are living in fantasy land', and after a while people would just start walking away."

The Grant brothers' revelation came two days after Livingstone suspended Lee Jasper, his race adviser, on full pay while the police investigate claims made in the Evening Standard that Jasper misused London Development Agency (LDA) grants. The mayor maintains that Jasper himself asked for the investigation and believes he will be exonerated.