Grant Shapps has been accused of “wrecking” talks with rail workers, as the RMT union announced strikes would go ahead on Thursday.
Fresh negotiations were held on Wednesday between the union, Network Rail and rail operators in a bid to break the deadlocked row over jobs, pay and conditions.
But there was no breakthrough and the RMT blamed the transport secretary for the impasse.
RMT general secretary Mick Lynch said: “Grant Shapps has wrecked these negotiations by not allowing Network Rail to withdraw their letter threatening redundancy for 2,900 of our members.
“Until the government unshackle Network Rail and the train operating companies, it is not going to be possible for a negotiated settlement to be agreed.
“We will continue with our industrial campaign until we get a negotiated settlement that delivers job security and a pay rise for our members that deals with the escalating cost-of-living crisis.”
RMT members at Network Rail and 13 train operators will walk out on Thursday following a stoppage on Tuesday, crippling large parts of the rail network.