The RMT union has warned that a "new phase" of industrial action will begin next month unless an agreement is reached between its members and London Underground (LU). 

The "further, escalated strike action" is due to begin on Monday, February 6, with the RMT warning that the current ban on working overtime will continue. 

The unions are campaigning to reopen ticket offices and have jobs reinstated, and have claimed that the former Mayor of London, Boris Johnson, imposed 838 job cuts on Underground workers. 

The recent Tube strike, which began at 6pm Sunday, January 8, and finished at 6pm on Monday, January 9, caused chaos for commuters as Underground stations were forced to close across the capital. 

The action also impacted overground services, with the whole of Clapham Junction station being forced to evacuate due to overcrowding. 

From Monday: Tube strike: Clapham Junction station evacuated amid rush-hour chaos as London Underground workers walk out

The conciliation service Acas has announced that LU will meet with the RMT and tne Transport Salaried Staff's Assocation (TSSA) on Monday to try and solve the dispute, after similar talks failed last week.

General Secretary of the RMT, Mick Cash, said: "RMT members have shown this week that they will not stand by while safety is compromised on London Underground off the back of cash-led cuts to staffinf levels that the union has warned would have a serious, lasting and corrosive impact for staff and passengers alike. 

"That is why our members have been forced to take this action. 

"RMT members on the London Underground stations see day in and day out the toxic impact of the job cuts programme, and they are reporting back that it is horrific.

"It has now also been shown that at management level there is agreement witht he union that the cuts have been a disastrous mistake and that the staff need to be put back on the stations. We now need a move away from the piecemeal and incremental approach to tackling this crisis and for LU to come forward with a serious package of proposals. 

"With the constant overcrowding on stations and platforms, it is only a matter of time before there is a major tragedy if we don't act decisively. Our dispute is about taking action to haul back the cuts machine and put safety back at the top of the agenda. 

"Today's decision gives ample time for LU to come forward with the serious package of proposals that is now required to kick-start the negotiations. The union is available for talks."