Unions representing staff at the track operator and all UK train firms want a breakthrough in the row before the end of the working day.

They claim the industry-wide Railway Pensions Scheme is in crisis, despite Network Rail saying it is "sound".

Unions want the scheme to stay open to all staff and a cap on contributions.

'Unacceptable'

The threat of the first industry-wide railway stoppage since the General Strike of 1926 comes from the Rail Maritime and Transport union (RMT), Aslef, the Transport Salaried Staffs Association (TSSA), and engineering unions in the Confederation of Shipbuilding and Engineering Trade Unions (CSEU).

They say they want an agreement reached with employers before "unacceptably high" employee contribution increases come into effect in July.

"Our members have packed into meetings around the country to tell us that they are not prepared to allow their pension scheme to disintegrate before their eyes, or suffer the massive contribution hikes that will be triggered on 1 July if no agreement is reached," said TSSA general secretary Gerry Doherty.

"Doing nothing means accepting the eventual collapse of the scheme and the prospect of poverty in retirement.

"That is simply not an option and if it means industrial action, then so be it."

An industry-wide stoppage would cripple the rail network.

'Improving position'

A spokesman for Network Rail said that "over the last three years we have worked with our employees and the unions to increase the scheme's funding levels and this has proved to be effective".

"Contributions for employees and employer will increase by a small percentage in the coming year to sustain the improvement in the funding position."

The ongoing railway pensions dispute comes as a thousands of civil servants have begun a 24-hour strike.

Staff at the Learning and Skills Council have walked out in a row over job cuts.