A Bill to extend the Brexit process has cleared the Lords despite fierce criticism from some Tories.
Peers gave the European Union (Withdrawal) (No 5) Bill an unopposed third reading after just 10 minutes of debate.
The Bill, placing a legal requirement on the Prime Minister to seek an extension to Article 50 to prevent a no-deal, now goes back to the Commons.
If MPs back changes made to the legislation in the Upper House during committee stage it stands ready to become law.
Promoted by Labour’s Yvette Cooper in the Commons, the Bill squeaked through the elected House by just one vote last week.
It ran into trouble in the Lords last Thursday when opponents tried to block the measure being forced through in just one day.
Labour threatened to keep the Lords sitting all night if necessary but an agreement between Opposition and Government whips stopped that happening with extra time provided today.
Lords leader Baroness Evans of Bowes Park said the Government still opposed the “unnecessary” measure.
Tory former leader Lord Howard of Lympne said: “This appalling piece of legislation is totally misconceived.”
Lord Howard said the “ludicrous” legislation aimed to constrain the Prime Minister’s exercise of the royal prerogative to make decisions on the exit date.
For Labour, Lord Goldsmith warned time was running out and it was critically important an extension was agreed before Friday.
Peers backed amendments to the Bill aimed at promoting legal certainty and avoiding the UK “accidentally” dropping out with no deal if the council came back with a counter proposal.
Another change made clear that nothing in the Bill prevented the Prime Minister from “seeking or agreeing” an extension, provided it was not earlier than May 22.
In the closing stages, Labour former Cabinet minister Lord Robertson of Port Ellen said it was a historic moment.
The UK was on the verge of talks which would determine the future of the country for generations to come and the Bill would play a part in that.
But Tory Lord Framlingham said it was all about “kicking the can down the road” when Britain should be leaving the EU with a “clean break” on Friday.
“This Bill is telling our Prime Minister what to do, a classic case of the tail wagging the dog and of constitutional chaos,” he said.
The Prime Minister is seeking a further Brexit delay to June 30 and EU leaders will discuss this at an emergency summit on Wednesday.
Mrs May spoke to Irish prime minister Leo Varadkar on Monday night about her recent letter to Donald Tusk and her desire to extend Article 50.
Mr Varadkar expressed his openness to the idea of extending the withdrawal deadline.
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Tory MP Daniel Kawczynski confirmed he has quit the European Research Group (ERG) of Conservative backbenchers because of its continued opposition to Mrs May’s Withdrawal Agreement passing the Commons at a fourth attempt.
Mr Kawczynski tweeted: “Have decided to resign from ERG. Despite excellent Chairmanship by @Jacob–Rees–Mogg who has accommodated all views I can no longer be a member of caucas which is preventing WA4 from passing.
“Hardcore element of ‘Unicorn’ dreamers now actually endangering #Brexit.”