A public -private partnership would pose "big safety risks" for London Underground, Ken Livingstone has warned a fringe meeting at the Labour party conference in Brighton.

He was "totally opposed" to privatisation of the tube, he said.

The London Mayor made his remarks at an Aslef and RMT sponsored meeting entitled "Devolution, democracy and the future of London Underground".

Referring to the contractors bidding to run London's tube network, Mr Livingstone said that the underground could not be run safely for a profit. "The more these companies spend on safety, the less they make in profit - it's in their interests to hold back investment," he explained.

Concerns about cost meant that he was being put under pressure by the government not to have trains on the East London line extension fitted with Automatic Train Protection - the safety system recommended after the Southall train crash - said Mr Livingstone.

Bottom of the Barrel

In an attack on the government's plans for the tube, Mr Livingstone denounced companies bidding to run London Underground as "chancers and spivs" who "were not at the respectable end of British capitalism".

Reputable firms had been put off bidding for the tube contract, he continued, when they saw that it could not be run safely at a profit - the government was now left with "the scum at the bottom of the barrel".

Bidders included firms who had profited from slave labour during the Second World War and who had previously been prosecuted for workforce deaths, promising: "We're going to keep watching these firms".

Bad for London

To applause and laughter from the audience, Mr Livingstone said that the successful bidder for the tube contract would not at first be obliged to improve on the performance of the network.

The proposed efficiency target for the first year is "5% below the existing performance rate," he said.

A recent report by the Industrial Society's Will Hutton on tube funding proved that a private-public partnership for the underground "is not in the interests of London," he argued. If the government persisted with the proposal he would seek a judicial review against the decision.

Treasury to Blame

Public sector services like the tube had been starved by the Treasury for years, London's Mayor said, because successive chancellors had been unwilling to spend money on them.

Mr Livingstone's stance was supported by Bob Crow of the RMT. London's tube network was "crumbling," he said, and as a result tube staff faced being "spat at and beaten up" by frustrated and angry passengers.