According to rail union RMT there are nearly 800 posts within the crucial Track Renewal Service (TRS) organisation.

This will be cut to around 260 for CP7 in response to funding cuts, which will see more essential works outsourced to contractors.

Despite finding cuts, the Office for Rail and Road has made clear that Network Rail should increase planned spending on renewals by £600m.

RMT general secretary Mick Lynch said that the work of the High Output Renewals Team, which uses specialised in-house on-track machinery, was crucial to renewals work and it would be lost forever if the work is outsourced as part of the managed decline of the industry.

He said: “These cuts represent further significant Network Rail cutbacks at a time when the industry needs to be developing its skill base not outsourcing the work to privateers.

“We have seen the impact of de-skilling and outsourcing on our railway network, a decline in safety and an increase in profiteering which combine to create a deadly concoction for workers and passengers alike.”