Network Rail said the redundancies were a result of new infrastructure which needs less maintenance and the weeding-out of outdated working practices.

The 500 workers will leave the company by the end of May following a voluntary redundancy programme. They join 235 volunteers who took redundancy in January while at least another 200 are expected to leave within the next few months.

RMT union leader Bob Crow accused Network Rail of trying to “con the public” and said he would re-ballot his members over strike action.

Network Rail currently employs around 18,000 people to maintain the railway. The firm said: “A combination of new infrastructure which needs less maintenance, together with the elimination of over-manning and outdated working practices, is allowing us to reduce employee numbers and costs while still maintaining a safe and efficient railway. It is expected that a further 200+ employees will leave the company under the voluntary scheme in the coming months.”

Steve Featherstone, Network Rail’s director of maintenance said: “More efficient maintenance means more investment in improving stations, opening new lines and adding capacity to allow more and longer trains. It is also good news for our employees – those who are leaving get a severance package and those who remain for the long-term will be part of a flexible and more skilled workforce who can deliver better value for money. That is the best way to safeguard skilled jobs in the future.”

Crow said: “NR is trying to con the public into believing that a cost-led jobs cull is safe when we already know that inspections and maintenance frequencies are overstretched and that most safety recommendations made after the Grayrigg crash have not been implemented in full or in part.

“NR knows as well as our skilled members that signalling systems need more maintenance, not less, that there is no widespread introduction of new technology, and that the conditions it wants to rip up have been negotiated in recent years.

“The fact is that NR is under pressure to slash 21 per cent from its budget, wants to axe 1,500 front-line posts, lump maintenance functions onto over-worked signallers, and impose changes that will undermine rail safety and make another disaster inevitable.

“The only part of NR that needs a jobs cull is the boardroom, whose latest wheeze will result in an increase in the ratio of over-paid executives on telephone-number pay and bonuses to front-line skilled staff, at the direct expense of rail safety.”