MPs have passed a bill giving the government the power to introduce its UK-wide welfare reforms in Northern Ireland.
The bill was given accelerated passage through the House of Commons on Monday night despite objections from Social Democratic and Labour Party (SDLP) and Ulster Unionist Party (UUP) MPs.
It is due to complete its consideration in the House of Lords on Tuesday.
MLAs voted last week to hand powers over the welfare system to Westminster.
That followed a new agreement between the Democratic Unionist Party (DUP) and Sinn Féin, Stormont's two largest parties, and the British and Irish governments.
The deal included a four-year package to soften the blow of the welfare reform and tax credits cuts, with a value of £585m.
Northern Ireland Secretary Theresa Villiers told the House of Commons the lack of resolution on welfare reforms had been "undermining the political process in Northern Ireland".
She said the new benefits system in Northern Ireland, with top-ups funded by Northern Ireland's ruling executive, would be the most generous in the UK.
Vernon Coaker, the shadow Northern Ireland secretary, said Labour would support the bill despite being opposed to much of the government's welfare reforms.
Attempts by the SDLP to amend the bill were rejected.
Mark Durkan, one of the party's MPs, accused the government of adopting a "kangaroo parliamentary procedure" to stifle debate and "fast-track" the bill.
"We would have liked to have more time just as our colleagues in the assembly when the debate arose there last week wanted to take more time - not just members of the SDLP, but members of other parties," he said.
"It is wrong that we are circumscribed on time. It is wrong that we are being muzzled."
But the DUP's Sammy Wilson said was "important that we have some urgency about this issue".
"It's taken long enough to strike the deal," he added.
Danny Kinahan, of the UUP, said the legislation was "most extraordinary".
He added: "It's actually a worse deal than what was on offer in the original Stormont House discussions."