The job losses are the result of plans to “modernise” the Tube network by closing ticket offices and moving staff to ticket halls and platforms.
A total of 950 jobs are at risk, although around 200 new jobs will be created when a new night Tube service starts in 2015.
The unions say the planned closures and redeployment of staff will make the Tube less safe and could make it harder for disabled and other passengers to get the help they need.
London Underground denies the changes will reduce passenger safety and says by moving staff out of ticket offices it will be able to provide a better service to Londoners and visitors.
Union members will hold two 48-hour strikes, the first of which will start at 21:00 Tuesday, 4th February and last until 20:59 Thursday 6th February. A second strike will be held on 11 February.
On Tuesday Transport for London revealed that of the 3,400 people eligible to leave the organisation on voluntary severance in 2015, 1,000 had requested details of their severance terms while “nearly 450 people have made a formal application to leave”.
A TfL spokesperson said the scale of applications meant that with natural turnover they would be able to achieve the job losses while avoiding compulsory redundancies.
Richard Tracey AM, the Conservatives transport spokesman on the London Assembly, said: “It’s bonkers these strikes are going ahead even though there won’t be any compulsory redundancies. In fact, in just the last three weeks, hundreds of staff have already volunteered to leave and over a thousand have formally requested details of severance packages.”
Mr Tracey has previously called for a ban on Tube strikes and the introduction of binding arbitration.
On Tuesday he said: “The system is broken and it’s high time the Government replaced public transport strikes with independent mediation.
“Furthermore, I’d like to thank the 6,387 RMT and TSSA members who ignored their militant union bosses and refused to vote for these ridiculous strikes. To all tube workers, even the few of you who voted for industrial action, do the decent thing, break these pointless strikes, and turn up to work as usual.”
