Emergency legislation to restore power- sharing in Northern Ireland by March has been rushed through the Lords.
The Lords debate followed a lengthy Commons session
The Bill, giving effect to the St Andrews Agreement, completed all its parliamentary stages in under 48 hours.
It became law late on Wednesday night before the transitional assembly's first meeting on Friday at Stormont.
During the Lords' passage former Northern Ireland first minister Lord Trimble raised the spectre of a "deadlocked assembly".
The DUP and Sinn Fein remain at odds over republican support for policing and the courts.
The bill - which the government hopes will pass into law before the end of the week - was debated in a six-hour session in the Commons on Tuesday.
It is expected to receive Royal Assent before the transitional assembly's first meeting on Friday.
Under the legislative timetable, established by the Northern Ireland (St Andrews Agreement) Bill, the transitional assembly will meet until 30 January when it will be dissolved for fresh assembly elections on 7 March.
One week after the results, parties who qualify for devolved ministries will nominate assembly members to Stormont's cabinet posts.
On 26 March, the new ministers will take office and devolution will return.
Lord Trimble, former Ulster Unionist leader, said there was an agreement between Tony Blair and Irish Taoiseach Bertie Ahern, but no-one else.
"The government is proceeding on optimistic assumptions which are not likely to be fulfilled," he cautioned.
For the Liberal Democrats, Lord Smith of Clifton called the Bill a "fig leaf to camouflage the almost irreconcilable elements at work".
He added: "Whether it will provide a foundation for operating a representative and democratic system of devolved government as all people of goodwill would wish is extremely doubtful."
Lord Glentoran, for the Conservatives, said there had to be "delivery" from Sinn Fein, "no more ambiguity, no more conditions, no more promises of action that don't happen".
Northern Ireland Minister Lord Rooker called for a period of prolonged stability to help the devolution process and insisted problems could be overcome if "everyone delivers on their commitments".
Former Conservative Cabinet minister Lord Tebbit said: "This Bill is another stage in the relentless march of Sinn Fein-IRA into power in Northern Ireland - power which has been won by bombs and bullets because it couldn't be won by the ballot box alone."