Two further rail strikes have been announced in August as the dispute over jobs, pay and conditions continues.
RMT general secretary Mick Lynch said: “The rail industry and the Government need to understand that this dispute will not simply vanish.
“They need to get serious about providing an offer on pay which helps deal with the cost-of-living crisis, job security for our members and provides good conditions at work.
“Recent proposals from Network Rail fell well short on pay and on safety around maintenance work.
“And the train operating companies have not even made us a pay offer in recent negotiations.
“Now Grant Shapps (Transport Secretary) has abandoned his forlorn hopes for the job of prime minister, he can now get back to his day job and help sort this mess out.
“We remain open for talks, but we will continue our campaign until we reach a negotiated settlement.”
Andrew Haines, chief executive of Network Rail, said: “By announcing even more strike dates, the RMT has dropped any pretence that this is about reaching a deal.
“It’s clear the best interests of passengers and our staff are taking second place to the union’s bosses’ political campaign.“
The companies involved in the RMT strikes are: Network Rail, Chiltern Railways, Cross Country Trains, Greater Anglia, LNER, East Midlands Railway, c2c, Great Western Railway, Northern Trains, South Eastern, South Western Railway, Transpennine Express, Avanti West Coast, West Midlands Trains, GTR (including Gatwick Express).
Following the news of further strikes, a spokesperson for the Rail Delivery Group, said: “This is a hugely disappointing announcement from the RMT’s leadership which will upset passengers’ summer plans, undermine struggling businesses and upend the industry’s recovery.
“We want to give our people an increase in pay, but asking taxpayers to shoulder more of the burden when they have already contributed £600 per household during the pandemic, or expecting passengers to fund it by paying more for their tickets, isn’t fair or sustainable.
“Instead, we have a responsibility to make changes to long-outdated working practices so we can adapt to post-covid travel patterns, bring our railway up to date and give our passengers a more punctual and reliable service.
“Rather than staging counterproductive strikes, we ask the RMT’s leadership to continue talking so we can come to a deal that works for our people, our passengers and for taxpayers.”
Earlier this week, the union announced a 24-hour strike for July 27, the day before the Commonwealth Games opens in Birmingham, after rejecting a “paltry” pay offer from Network Rail.
The offer was for a four per cent pay rise backdated to January, another two per cent next year and a further two per cent conditional on achieving “modernisation milestones”.
Separately, train drivers at eight rail firms have agreed to to strike on July 30 in a dispute over pay, union Aslef has said.
Announcing the strike this week, Aslef accused train companies of failing to make a pay offer to keep pace with the increase in the cost of living.
Mick Whelan, Aslef general secretary, said: “Strike action is, now, the only option available but we are always open to talks if the train companies, or the government, want to talk to us and make a fair and sensible offer.”
The walk outs are set to cripple rail services this summer, and it is another blow for commuters and businesses hit with severe disruption by a series of national strikes were held in June.
It could have even more impact than during last month’s strikes by 40,000 RMT workers.
RMT members have been in negotiation with operators over pay and job losses.