Controversial "sacking of nurses" laws will be revoked when Labour comes to power, a peer has vowed.
Unions have warned that the controversial Minimum Service Levels Bill championed by the Government could strip 5.5 million workers of their right to strike.
Today the House of Lords backed a string of amendments aimed at better scrutinising ministers if they apply it, but heard the bill's impact remains to be seen.
It comes after Tory heavyweight Jacob Rees-Mogg told the Commons earlier this year that the legislation was "badly written".
Labour peer Lord Ray Collins of Highbury said: "This is a skeleton bill and we don't really know what it means in terms of legislation.
"I think the remark of the noble Lords' friend Jacob Rees-Mogg sums it up really.
"MPs don't have any idea about the practical implications of the implementation of the powers that will be granted to ministers... there's no proper scrutiny."
And he continued: "As I said at every stage of the bill going through, when Labour returns to Government fairly shortly, we will repeal this legislation."
The Government pushed through the bill - which will return to the Commons for consideration of amendments - following a wave of public service strikes.
Unions say that when workers lawfully vote to strike in health, education, fire, transport, border security and nuclear decommissioning, they could be forced to attend work - and be sacked if they do not comply.
In January Labour's Angela Rayner dubbed it the "sacking of nurses bill" in a punchy exchange.
Lord Collins praised former TUC leader Baroness Frances O'Grady - a recently appointed Labour peer - for her work pushing for safeguards.
Yesterday TUC general secretary Paul Nowak fumed: "This Conservative Government is threatening the right to strike of as many as one in five workers up and down the country.
"This is a spiteful Bill. No-one should be sacked for trying to win a better deal at work, but this draconian legislation would mean that when workers democratically vote to strike, they could be forced to work and sacked if they don't comply.
"It's undemocratic, it's unworkable and it's very likely illegal.
"Ministers have tried to keep the public in the dark about the true nature of this Bill.
"They are ramming it through - shortcutting normal parliamentary procedures and ducking scrutiny, and they are giving themselves the power to snatch away the right to strike of five-and-a-half million workers."
The government argues that the move is necessary in order to protect the public, despite unions themselves agreeing to ensure emergency cover during recent NHS strikes.
