Metronet collapsed into administration recently, four years into a controversial PPP costing £17 billion. Jobs are going to be transferred to Bombardier, one of the stakeholders in the Metronet consortium.

Bob Crow, RMT general secretary, said: "Our members have said with a single, united voice that they are not prepared to be made to pay for the failure of the PPP with their jobs, conditions or pensions.

"The work our members do is crucial not only to the day-to-day operation of the Tube but to the urgent upgrades that are slipping further behind schedule, and any further fragmentation of the workforce is out of the question."

Ernst and Young informed all unions at Metronet, including the RMT, Unite and TSSA that any agreements with the company were void now it's in administration, this applies to pay, conditions, pensions and forced job transfers.

In the RMT ballot, there were 1,123 (98.3 per cent) votes to strike, with 20 votes (1.7 per cent) against, on a turnout of 51 per cent.

In the TSSA ballot, there were 127 votes for strike action (77 per cent) and 38 votes (23 per cent) against, on a 48 per cent turnout.

In the Unite ballot there were 119 votes for strike action (90%) and 12 votes against (10%) .

Also, station staff on the Bakerloo line are about to resume a second 24 hour strike over health and safety, where workers are expected to de-train passengers alone, RMT members voted 94.5% in favour of strike action.