London Underground workers have voted overwhelmingly in favour of further industrial action, it was announced last night.

Nearly 80 per cent of the votes cast by members of the RMT union were in support of the strikes, in protest against an imposed three per cent pay increase.

The Aslef trade union, which represents train drivers, is also expected to ballot members on action over the same deal, which could fall on the same days as that by the RMT.

Strikes were co-ordinated by the unions earlier this year, bringing the network to a standstill.

Bob Crow, RMT general secretary, argued that over the past decade, passenger numbers had increased on the tube by 30 per cent and revenue more than doubled, while staff numbers had fallen by a third.

"Our members are angry that London Underground has not only refused to go to independent mediation to settle this dispute but have actually lowered its pay offer because we would not sign away our right to strike," he said.

"Mediation settled the last pay dispute and there is no reason why it should not settle this one but LU knows that three per cent is too low, in fact it is the lowest offer from any train operating company this year."

The union is expected to announce strike dates later this month.