Thousands of rail jobs could be axed by Network Rail under a shake-up of working practices to cut costs after the Covid pandemic, according to the industry’s biggest trade union. The Rail, Maritime and Transport workers’ union (RMT) said it had “no alternative to move to a national dispute footing” to protect its members’ livelihoods and safety. In an email to staff seen by the Guardian, the Network Rail chief executive, Andrew Haines, said that to deliver a safe and affordable railway “change needs to happen. A decision to stay as we are is untenable,” adding: “This will be tough for every one of us.” According to the union, which has been locked in pay talks with the owner of Britain’s rail infrastructure, the government has demanded savings in rail after underwriting services during the Covid-19 pandemic, when the public has been told to avoid travel. Rail services are running at about 75% capacity, with passenger numbers just over 20% of pre-Covid levels. The government has said it is spending billions to make up for lost fare income since the start of the pandemic. The RMT said Network Rail wouldunveil plans next week to halve the frequency of maintenance work, which it estimated could mean up to one in three of about 14,000 affected workers being laid off. According to Network Rail sources, there were no concrete proposals for job or work reductions although they were in “early talks” with the union over modernising work practices. Responding publicly to the RMT, Haines said: “Outdated practices, and the impact of Covid on passenger numbers, show that the railway is not serving passengers, taxpayers or staff as well as it should. “That’s why we want to work constructively with the unions to create an industry fit for the 21st century that is genuinely safe, efficient and effective for everyone. I hope the unions will recognise and embrace the need to modernise and will work with us to improve Britain’s rail network.” Network Rail is pushing an open-ended pay freeze and a reduction in conditions, according to the RMT. The union’s general secretary, Mick Cash, said: “Under orders from the government, Network Rail is using the Covid-19 drop in passenger numbers and service levels to rush through the most radical restructuring of the railway infrastructure since privatisation. “Rather than the post Covid-19 return to rail recovery which our economy and climate desperately needs this is a return to the disastrous days of Railtrack where cutting costs and corners led to a string of fatal accidents.” Railtrack, a private company set up after UK rail privatisation in 1994 to run the infrastructure, was disbanded in 2002 after three major disasters in five years. It was replaced by Network Rail, a state-owned body. The union said it was moving to a national dispute. Mick Lynch, the RMT’s chief negotiator and a leading contender to succeed Cash in union elections in May, said: “There’s never a good time to go on strike but we believe they want to implement these measures now. We’ve got no choice but to respond strongly. “They will double the period between [track] inspections. That will not only import danger but will be a drastic cut in jobs.” The future shape of the rail industry is still being discussed by the government, which announced the end of traditional franchises during the pandemic and continues to subsidise lost revenue through emergency recovery contracts for train operators. Network Rail’s infrastructure budget was cut by £1bn in the autumn spending review.