Rail passengers have faced another day of disruption, with the union leader Mick Lynch warning the dispute could go on “indefinitely” unless ministers intervene in talks. Only 20% of train services across Great Britain were running on Thursday due to strike action over pay, jobs and conditions that involved more than 45,000 rail workers, who are members of the Rail, Maritime and Transport (RMT) and TSSA unions. Commuters were told to only try to travel if absolutely necessary, with further disruption planned on Friday and the weekend. In London, bus drivers and London Underground workers plan to strike in the coming days. Lynch, the RMT’s general secretary, said the strikes could be prolonged “indefinitely” unless the government ended its stance of refusing to get involved in negotiations. Speaking from a picket line outside Euston station in London, Lynch said: “Using taxpayers’ money to satisfy the anti-union agenda of the Tory party and seek to break the trade unions is shameful, and means the dispute will be prolonged indefinitely as the train companies don’t lose a penny as a result of the industrial action and therefore have no incentive to settle the disputes. “Instead of waging an ideological war against rail workers, millions of voters would rather that the government allow for a fair negotiated settlement.” The RMT says it has calculated that, including the previous and forthcoming industrial action, more than £120m of taxpayers’ money has been used to “bail out” private train companies to date. In a letter to the transport secretary, Grant Shapps, Lynch said: “Your government has made the decision to use taxpayers’ money to bail out private train companies from being liable for revenue lost because of industrial action on the condition the same companies comply with government instructions to hold down pay, cut thousands of safety-critical rail jobs, introduce driver-only trains and close ticket offices across the network.” On Thursday, many routes and stations were left with no services at all, while trains still running were only operating between 7.30am and 6.30pm. A Department for Transport spokesperson said: “All these strikes are doing is hurting those people the unions claim to represent, many of whom will again be out of pocket and forced to miss a day’s work. “We urge union bosses to do the right thing by their members and let them have their say on Network Rail’s very fair deal, which will deliver the reforms our rail system urgently needs. “It’s time to get off the picket lines and back around the negotiating table – the future of our railway depends on it.” According to the track operator Network Rail, 4,300 rail services were due to run on Thursday and Saturday, an increase on the number during previous national RMT strikes. However, the industrial action left some places, such as Portsmouth, Swansea and Blackpool, with no train services at all. Services will also finish earlier, with the last train from London to Leeds due to leave at 3.05pm. Network Rail’s chief executive, Andrew Haines, said negotiations with unions were “slow” and “painful” and there was “an absolute lack of clarity over what it would take for this strike to be called off”. He told BBC Radio 4’s Today programme: “We’re desperate to bring this to a resolution in a way that is affordable for the country and which avoids the pain for my colleagues.” Meanwhile, Luke Chester, the organising director at the TSSA, told BBC News: “The reality is that what we need to resolve this dispute is a pay rise which reflects the cost of living increase that is affecting most people in this country very severely.”