Legislation to set the date of the next general election at 7 May, 2015 and for future polls normally to be held every five years has completed its Lords stages and now returns to the Commons.
The government was defeated earlier this month when peers voted 190 to 184, majority six, to let each Parliament decide whether to invoke the provisions of the Fixed-term Parliaments Bill.
Ministers are expected to ask MPs to overturn the defeat. Every detail of the Bill must have the consent of both Houses for it to become law.
The government has also changed the Bill, following criticism from two ex-speakers, to avoid the need for the Commons Speaker to “certify” when a vote of no confidence can lead to an early general election.
Lord Bach, for Labour, said during tonight’s third reading: “This is a completely wrong way of passing constitutional change in this country and I believe, if there had been a free vote, it certainly would have been four years rather than five.”
The shadow justice minister said he hoped the Bill would be “accepted by the House of Commons as it leaves here today”.
Tory ex-MP Lord Cormack, who rebelled in the earlier vote, said the amendment had made a “not terribly good Bill slightly better” and he urged ministers not to overturn it.
Advocate General Lord Wallace of Tankerness (Lib Dem) confirmed that ministers were “not able to support” the amendment, which was moved by crossbencher Lord Pannick QC. “No doubt the Commons will consider its constitutional novelty,” he added.
“Subject to what I have said about that one amendment,” he said, the Bill was now in better shape.