Workers at dozens of train companies and maintenance firms will vote on industrial action if the deadlock is not broken by April 28.

If the strike goes ahead, it will be the first industry-wide stoppage since the General Strike in 1926 and will cripple the rail network, causing travel chaos across the country.

The industry's unions are calling on employers to agree to a formula to avert what they described as a "pensions crisis".

The Rail Maritime and Transport union, Aslef, the Transport Salaried Staffs Association and engineering unions in the CSEU are campaigning to ensure that the Railway Pensions Scheme remains open to all employees and that worker contributions are capped.

The unions have warned that they want an agreement reached before "unacceptably high" employee contribution increases come into effect in July.

The dispute involves every train operator, Network Rail and dozens of infrastructure companies.

Bob Crow, general secretary of the RMT, said: "We have written to every employer in the scheme seeking an unconditional undertaking on our key demands and if that is not received by April 28, we will be in dispute and the next step will be ballots for strike action.

"We have asked the Government to help get the employers around the table but have had no response so far."

Gerry Doherty, general secretary of the TSSA, said: "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 July 1 if no agreement is reached.

"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."

Bob Rixham, of the Confederation of Shipbuilding and Engineering Unions, said: "We are calling a halt to attacks on our hard-won pension rights and it is time for the Government and employers to start taking us seriously."

A spokesman for Network Rail said: "Our scheme is sound and 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."