Tory ministers have been forced into yet more U-turns on the controversial Trade Union Bill.
In a bid to avoid defeat in the House of Lords next week, Business Secretary Sajid Javid today tabled eleventh-hour concessions on key issues such as e-voting and opting in to party funding for Labour.
Trade unions have claimed that the bill is the worst attack on their rights for decades and have fought a rearguard action to get changes before it becomes law.
The bill aims to force trade union members to 'opt in' to a political fund rather than 'opt out': a move that could cost Labour an estimated £6m a year.
But amid fears of losing union support for the 'In' campaign in the EU referendum, ministers have now agreed to allow a pilot scheme for electronic voting for strikes and other changes.
Unions will be given 12 months, rather than the original three months, for their transition to the new scheme.
However, HuffPost understands that even bigger concessions could emerge after another Lords defeat, with pressure to extend the transition period to two years.
Ministers are running out of time to get the legislation on the statute book before the end of the Parliamentary session in mid-May.
Today's concessions also change the requirements on renewing 'opt-ins' every five years, although again a 10-year period is still being sought by critics.
The Government has agreed for the first time that union certification officers will also be given a role in exercising oversight of the new rules.
There remain some key differences over the 'opt in' plans that form the heart of the bill.
MPs are set to vote on the concessions on Wednesday, when Lords amendments on the bill are due to be debated.
If the Commons approves the changes, they will then go to the Lords next week.
Ministers unveiled other concessions last week in a bid to save the Bill from getting bogged down, agreeing to drop bitterly-fought 'check off' plans to stop unions from automatically taking subscriptions from public sector salaries.
Unison has also welcomed a U-turn on allowing trade union members 'facility time'.
The Bill has been opposed by the TUC and Britain's biggest unions, from Unite to Unison to the GMB and PCS.
Former civil service chief Lord Kerslake has attacked the bill as 'worryingly authoritarian'.
And several Tory peers have claimed that its attack on party funding breaks the usual convention of seeking cross-party consensus first.
Unions and Labour were assessing the amendments this afternoon to gauge their impact.
TUC general secretary Frances O'Grady has led the campaign to get the Government to change its stance.
The Prime Minister's official spokeswoman said that the amendments reflected the Government's wish to "get the balance right between the interests of the trade unions and the interests of the majority of people affected by strikes to services".
Asked if the concessions were part of a wider move to keep trade unions on board for the EU referendum, the spokeswoman said: "We want to get this bill through the House of Lords and as part of that we will engage with them."
"The Prime Minister has offered the referendum to every person in this country and would encourage them to use it."
Katie Ghose, Chief Executive of the Electoral Reform Society, told HuffPost UK:
“After months of campaigning, it’s welcome news that the government have listened and made some much-needed changes to the Trade Union Bill.
“The decision to give unions a year to transition towards making members ‘opt in’ to their political funds is a positive step. This 12 month period is a real window of opportunity for all parties to get around the table and sort out our broken party finance system once and for all.
“The fact that Ministers are conceding that unions can trial e-voting is also a positive move. Participation in civil society is fundamentally a good thing – it should be encouraged by increasing the ways in which union members can vote, not discouraged by artificially narrowing the space for taking part.
“Finally, it’s good to see the government will now allow members to opt in to union political funds online. Under the Bill as it stood before, they would only have been able to hand in a form in person or via post – a bizarre anachronism in a digital age.”