The Government will face the most widespread industrial action in the rail industry for a generation if it presses ahead with plans to cut workers’ pay, a union leader has warned.

Transport Secretary Chris Grayling sparked anger when he proposed linking pay rises to CPI inflation rather than the higher RPI figure.

In speeches to the TUC Congress in Manchester, rail union leaders lined up to attack the move and warned of strikes.

Mick Cash, general-secretary of the Rail, Maritime and Transport union, said: “Chris Grayling has made it crystal clear that he intends to try and impose a nationwide pay cap on RMT members linked to the bogus CPI inflation figure.

“Any such move would rob workers of thousands of pounds across Network Rail, the train operating companies and quite possibly London Underground as well.

“The CPI measure Grayling is promoting doesn’t even take into account the cost of a roof over your head and if he seriously thinks that our members are going to take the hit to their pay for his incompetence and the greed of the train companies, he has got another coming.

“RMT will be mobilising a national campaign to smash the pay cap, which will include the use of co-ordinated industrial action if required to protect and enhance our members’ pay and conditions.

“We will ballot for strike action – it will be the biggest industrial action for a generation if they don’t back down.”