The UK government's strike law is a "fundamental attack" on workers, and politicians "of all stripes" are worried about the legislation, according to Frances O'Grady. The Trades Union Congress (TUC) general secretary also told IBTimes UK that the controversial Trades Union Bill had been pushed through without evidence or consultation.

"This bill also attacks union funds, there are large parts of it that weren't written down in the Conservative Party manifesto, and of course the government's own independent regulatory policy committee said that this bill is not fit for purpose," she added.

The comments come as the bill faces its report stage in the House of Commons on 10 November. The measure would mean, among other things, that workers would have to hit a 50% turnout threshold for a strike vote to be considered legal.

But the government has argued that the legislation is "fair" and will help stop the disruption of public services. "People have the right to know that the services on which they and their families rely will not be disrupted at short notice by strikes supported by a small proportion of union members," a spokesperson for the Department for Business said.

"The ability to strike is important but it is only fair that there should be a balance between the interests of union members and the needs of people who depend on their services."

Hundreds of trade unionists turned out at Central Hall in Westminster to rally against the bill. The TUC also launched a new advertising campaign, which features a midwife, a firefighter and a cinema worker who have "reluctantly taken strike action in recent years".

The legislation has also proved controversial among some Tory backbenchers. David Davis, the former Conservative chairman and leadership contender, compared the bill to anti-trade union measures introduced by Spanish dictator General Franco.

"I agree with most of the Trade Union Bill – I think it's very sensible," Davis told Sky News on 14 September. "But there are bits of it which look OTT, like requiring pickets to give their names to the police force. What is this? This isn't Franco's Britain, this is Queen Elizabeth II's Britain."