Ministers cannot allow unions to win the battle for higher pay as it would fuel a “vicious cycle” of inflation hurting the poorest, Deputy Prime Minister Dominic Raab said.

Mr Raab told Sky News’s Kay Burley that latest official inflation figures showing the increase in the cost of living hitting a new four-decade high of 9.1% illustrated why public sector pay restraint was needed.

He indicated that the publicly-backed rail sector would continue to hold out against RMT demands for a 7% pay increase amid the biggest train strike in three decades and threats for wider industrial action across the economy and public sector later this year.

Travel disruption continues as talks to end rail strikes resume – live updates

Mr Raab argued that big wage increases would help inflation stay higher for longer, eating into the value of incomes.

He said: “We really do understand the pressure that those on low incomes are facing at the moment, they’re struggling to make ends meet.

“We do need to have the the kind of pay restraint in the public sector that we have been talking about… otherwise we’ll just have the vicious cycle of inflation staying higher for longer.

“We can’t allow the unions in this very militant way that they have proceeded to win this argument because it will only hurt the poorest in our society.”