Rail workers are to take four days of strike action from April 6, the Tuesday after Easter.

The Rail Maritime and Transport union (RMT) has announced the industrial action as it is embroiled in a row with Network Rail (NR) over jobs and working practices.

Negotiations over the firm's plans to cut 1,500 maintenance jobs were held this week at the conciliation service Acas. But talks were adjourned on Thursday night without agreement.

The union's 12,000 NR maintenance workers, and TSSA's 800 members working as supervisors, will stage an all-out strike which threatens the worst disruption for 16 years.

RMT general secretary Bob Crow said: "It remains the case that Network Rail, in a drive to slash 21 per cent from their budget, want to axe 1,500 maintenance posts, lump maintenance functions on to over-worked signallers, rip up agreements and impose changes that will quite clearly undermine safety across our railways and make another Hatfield, Potters Bar or Grayrigg disaster an inevitability."

TSSA general secretary Gerry Doherty said: "The Office of Rail Regulation agrees with us that these changes pose a threat to safety. It is time that Iain Coucher (NR chief executive) started listening to his staff and the rail regulator."