Tories have called for curbs on trade unions' powers to call a strike, with Boris Johnson encouraging the government to show "some Thatcherite zeal" against potential industrial action this year.

In an echo of the late Baroness Thatcher's campaign against union influence in the 1980s, the London mayor said it was "farcical" that a strike could go ahead without the backing of the majority of members eligible to vote.

He told The Sun: "It often results in a strike backed by just one in 10 union members, antagonising millions of commuters in the process and costing London and the UK billions every year.

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"I'd urge the Government to act with some Thatcherite zeal and at the very least legislate against strikes supported by less than half of all union members."

Johnson's most troublesome union leader - Bob Crow, general secretary of the Rail, Maritime and Transport union, which has called Tube strikes in the capital - accused the mayor of starting a "campaign to destabilise (Prime Minister David) Cameron."

A recent report by the Conservative group on the London Assembly estimated Tube strikes cost the economy £48 million a day, and that industrial action between 2005 and 2009 cost £1 billion.

The call for new laws making it illegal to take action without the majority of members' support follows unions raising the prospect of a general strike in protest at the Government's austerity measures.

The proposed 24-hour walkout - backed earlier this month by the country’s two biggest unions - would be the first time since 1926 that private and public-sector workers have co-ordinated a nationwide mass action.

Tory MP Dominic Raab, who is leading a campaign for fresh powers, also told The Sun: "Margaret Thatcher injected a dose of democracy into the unions, to empower their members and protect Britain.

"We now face a hot summer of discontent, with reckless strikes from schools to airports that most union members refused to back.

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"It's high time we had extra safeguards to protect the hard-working majority from this abusive militant minority."

His fellow backbencher Priti Patel said: "Defending the rights of people to work without fear of intimidation, bullying or violence is exactly what Margaret Thatcher championed and this legislation could once again put the rights of workers above the vested interests of the left and their union barons."

But TUC general secretary Frances O'Grady said the move to impose a turnout threshold on strike ballots would be "grossly hypocritical" when MPs did not need the support of 50% of all voters to win election.

She said: "The truth is that union members - particularly in the emergency services - are always reluctant to take strike action and only do so when no other way of resolving a dispute is available and only after a proper ballot.

"The first thing that any dictator does is attack democratic unions."

Mr Crow said: "This is the same old union-bashing, Thatcherite rhetoric from Boris Johnson and his cheerleaders in the Tory Party as they wind up his campaign to destabilise Cameron on the back of ripping up workers rights.

"They know full well that any provocative attempt to turn transport workers into forced labour rather than a free workforce would lead to a total shutdown in the capital.

"This bunch need to cut out the rhetoric of the dictator, and the hypocrisy of having one form of democracy for the boss class and another for the working class, and get on with doing their jobs instead of posturing across the media."