As London seeks more energy from “crucial” combined heat and power, the government is getting tied up in a “meaningless debate” about nuclear energy.

The comments were made by mayor Ken Livingstone during a mayoral race panel debate at the London office of CB Richard Ellis.

Livingstone and candidates from the Liberal Democrats and Green Party were taking questions from the audience at the evening event in front of around 50 property developers.

All three candidates for the mayor’s job on 1 May agreed that CHP was the way forward. They were responding to a question from BSJ asking whether the candidates would do anything to encourage the development of large scale CHP and biomass plants.

“There is this ridiculous debate about whether we’ll have nuclear power stations, coal fired stations or gas. They are all crap as an economic prospect,” said Labour incumbent Livingstone.

“Sixty-five per cent of the energy consumed by any large power station is flushed away into the sea or local river in terms of cooling system or steam into the air. Our commitment is to get local energy from combined heat and power like there is on the Barking site at the Isle of dogs and therefore get a15% wastage, versus the 65% wastage from current power stations. It’s an arcane debate the government has got itself into. The truth is they are all pretty grim. CHP is clearly the best way forward.”

Brian Paddick of the Liberal Democrats, and former deputy chief of the Met, said CHP should not be just for new-build residential projects: “Only 1% of dwellings in London is new-build so the most important gains are to be made with the existing housing stock. We must bring this into play if we wish to see a real impact on reducing CO2.”

Green candidate Sian Berry, an electrical engineer by training said that there is “no excuse for wasting heat and big power stations do that on a colossal scale”. Berry was principal speaker of the Green Party before stepping down to run as their candidate.

Livingstone is seeking his third four-year term after winning the first race in 2000 and being re-elected in 2004.

London-born and Oxford-educated Paddick retired from the Met as deputy assistant commissioner in May 2007. He was police spokesperson for the funeral of Diana, Princess of Wales and worked closely with the Muslim community after the London bombings on 7 July, 2005.

Tory candidate Boris Johnson was absent from the debate due to diary conflicts.