The Transport Secretary has been accused of damaging the prospects of resolving a series of bitter rows over the role of guards and driver-only trains after he attacked the biggest union involved in the disputes.
Chris Grayling wrote to MPs saying a series of strikes by the Rail, Maritime and Transport union next month were aimed at "deliberately" disrupting passengers.
He wrote: "I want to assure you that the RMT's dispute is not about jobs: affected staff have been offered cast iron guarantees by the train companies involved.
"This dispute is not about money: affected staff have also been offered pay guarantees. And this dispute is not about safety: driver controlled trains have been ruled as safe by the regulator, and have been operating safely on some of the busiest parts of the rail network for 30 years.
"What the RMT is insisting on is that trains full of passengers, which are perfectly capable of operating safely, should be cancelled just because a second staff member, a guard or conductor, is taken ill or delayed on an inbound train."
He told MPs to reassure their constituents that he would be taking every step to ensure that as many people as possible can use the railway during strikes on Southern, South Western Railway, Merseyrail, Greater Anglia and Arriva Rail North (Northern).
Contingency planning was "well under way" and Mr Grayling said he would write to MPs again before the strikes, which will last for 24 or 48 hours from November 8.
RMT general secretary Mick Cash said in a letter to Mr Grayling: "It is abundantly clear to passengers that it is your proposals under the strategic direction of your department to remove the train guard from railway services on Southern, Northern, Greater Anglia, Merseyrail and South Western Railways that is preventing the companies from reaching safe and effective agreements with the RMT.
"I do not say this lightly and a number of train operating companies are privately indicating to me that that you are sabotaging the deals that in normal circumstances they would be able to make."
Mr Cash commented: "This letter from Chris Grayling nails down once and for all the core fact that it's the Government who are imposing Driver Only Operation on the train operators and who are directing the attack on Britain's train guards.
"Instead of allowing normal industrial relations to run their course, the train companies are boxed in by central diktat from Chris Grayling and the Department for Transport.
"When it comes to the reasons for the current disputes, Mr Grayling's letter is a wholly misleading work of fiction that damages the prospects of reaching a negotiated agreement with the train companies for clearly politically motivated reasons.
"This unprecedented political interference explains why RMT has been able to reach negotiated settlements over the guards and the method of train dispatch in Scotland and Wales, where responsibility is devolved, but have had the door slammed in our face in England when it comes to any meaningful talks.
"Chris Grayling's letter to MPs shows that the Government are driving the current rail disputes for their own politically-motivated reasons.
"That damaging and dangerous behaviour needs to stop now and normal industrial relations should be reinstated."