Tory leadership favourite Liz Truss has launched an attack on union chiefs as she drifts further to the right to win over party members.
The Foreign Secretary announced she would bring in tough new laws that would limit workers' rights if she makes it to Downing Street.
Union chiefs have warned that curtailing the right to strike means working people lose the power to bargain for better pay and conditions.
Ms Truss plans to introduce new legislation in her first 30 days of power to guarantee a minimum level of service on vital national infrastructure.
Boris Johnson had already been working on new laws to make industrial action such as rail strikes illegal unless a certain number of staff are working.
Ms Truss also wants to raise the minimum threshold for voting in favour of strike action from 40% to 50%. Turn out for the latest round of strike was well over 80%.
The minimum notice period for strike action would be raised from two weeks to four weeks, and a cooling-off period would be implemented so that unions can no longer strike as many times as they like in the six-month period after a ballot.
Ms Truss would also put an end to members receiving tax-free payments from trade unions on the days they are on strike.
She said: "We need tough and decisive action to limit trade unions' ability to paralyse our economy.
"I will do everything in my power to make sure that militant action from trade unions can no longer cripple the vital services that hard-working people rely on."
It comes as rail services are set to be severely disrupted on Wednesday with thousands of workers staging a fresh strike in a bitter dispute over jobs, pay and conditions.
Members of the Rail, Maritime and Transport union (RMT) at Network Rail and 14 train operators will walk out, crippling services across the UK.
Labour's Deputy Leader Angela Rayner said: " Liz Truss is looking to blame anyone and everyone else other than herself for the mess the Conservatives have made of the last 12 years.
"Her latest Tory fantasy is dangerously out of touch with reality and ignores the stubborn fact that she has sat around the Cabinet table for nearly a decade of pitifully low wage growth, crumbling public services and sleaze at the heart of Government.
"As we saw with the Government's plans to break strikes with agency workers, these plans are unworkable, will only erode working people's rights further and inflame industrial relations at a critical time."
TUC general secretary Frances O'Grady added: "The right to strike is an important British freedom.
"Threatening the right to strike means working people lose the power to bargain for better pay and conditions.
"Instead of taking potshots at working people and their unions, the candidates should come up with plans to get wages rising again. That's how to deal with the cost-of-living emergency."
