After a marathon all-night debate in the House of Lords on proposals for a referendum on changing the Westminster voting system and cutting the number of MPs, peers discussed the matter for just 80 minutes when business resumed today.
The ninth committee day on the Parliamentary Voting System and Constituencies Bill, which has already cleared the Commons, began at 3.48pm yesterday and did not end until 12.51pm today.
The House was restarted at 2.15pm for the introduction of three new members and oral questions before peers dealt with three sets of amendments on the Bill and adjourned at the unusually early time of 4.34pm.
Although the atmosphere in the chamber was noticeably more co-operative than yesterday, it remains unclear whether the Government will succeed in its aim of having the legislation on the statute book by 16 February.
That is the deadline required for a referendum to take place on 5 May, as the Government intends, on a move from the "first-past-the-post" system of electing MPs to the "alternative vote" (AV) system.
And peers may face another late night tomorrow when the 11th committee day begins at 3.30pm as the Lords must not only complete the committee stage of the Bill but its report stage and third reading before it can become law.
Unlike in the Commons, the Government cannot guillotine debates in the Lords and Labour has been pressing ministers to delay their plans to cut the number of MPs from 650 to 600 if they want the voting referendum to go ahead as planned.
Government chief whip Baroness Anelay of St Johns indicated at the end of the marathon sitting that today's business would end before the usual rising time of 10pm.
But the speed with which the three groups of amendments - the target set by the Government to complete today - were dealt with was in stark contrast to last night's slow progress.
The 21-hour debate, which saw long speeches and numerous interventions, had covered just eight out of 66 remaining groups of amendments to the legislation.
It was preceded by angry exchanges between Lords Leader Lord Strathclyde and shadow justice minister Lord Falconer of Thoroton over whether Labour peers were deliberately trying to "talk out" the measure.
Lord Strathclyde was less combative at the start of today's debates, when he told peers the House was "in the most unusual situation" that Monday in the Lords had only very recently become Tuesday.
"Your Lordships are looking remarkably sprightly - I am almost tempted to do it all over again," the Tory Cabinet minister quipped.
He commended the Lords staff for their back-up for the all-night sitting, including camp beds for "the lucky few" and "a most delicious breakfast" in the early hours.
He went on: "There is considerable pressure and concern throughout the House of those who wish to find a way to progress business which, by all measures, is going extremely slowly and to find ways to respect the convention that the House passes Government business in reasonable time.
"We are about to go into committee for the 10th day and I am hopeful that today's progress will be somewhat more speedy than yesterday's."
Lord Falconer told peers: "What has made this House successful over the years is finding solutions to the sorts of problems we currently face."
Lord Falconer confirmed he remained "willing to discuss" procedures and the content of the Bill with a view to bringing "an end to the position".
Peers then spent 74 minutes debating one group of amendments and the next two groups were completed in just six minutes before the adjournment.
In a symbol of the changed atmosphere in today's short sitting, Labour's Lord Campbell-Savours at one point intervened on fellow Labour peer Lord Davies of Stamford in an attempt to curtail a contentious speech he was making.
Lord Campbell-Savours, a stalwart of the lengthy debates on the Bill, said: "We're having a very constructive debate on this amendment and I do appeal to all my colleagues to try and conduct ourselves in a way where we may get some compromise on this amendment."
Tory the Earl of Onslow had earlier said that if Lord Davies' speech was not a filibuster "I don't know what is". He accused the Labour peer, a former Tory who swapped sides while in the Commons, of bringing the House "into absolute disrepute".
The brief heated exchange came during debate on an amendment moved by Lord Falconer that would have given greater flexibility to the Boundary Commission to set the size of constituencies to take account of matters such as geographical features.
Under the Government's plans the number of electors in a constituency can only vary by 5% either side of a fixed quota.
But Lord Falconer argued the Boundary Commission should be able to increase the flexibility to 10% if there were "overriding reasons".
Lord Wallace of Tankerness, replying for the Government, said the 5% provision allowed for flexibility, but pushed by crossbench QC Lord Pannick said he would "consider" the issue further but insisted he was not in a position to offer any concessions.
Earlier, Baroness Warsi, co-chairman of the Conservative Party, accused Labour leader Ed Miliband of being either weak or unable to control his own party.
Speaking outside the chamber, she said: "These time-wasting tactics by former Labour MPs are preventing the public from having a say on a policy Ed Miliband claims he supports.
"His failure to act is either a sign he is weak and cannot control his own party or that he is being opportunistic and playing politics ahead of an important referendum.
"Ed Miliband needs to say clearly whether he supports these tactics or an AV vote."
And Liberal Democrat party president Tim Farron wrote to party members asking them to call on Labour peers and MPs to end their "filibuster" of the Bill.
Mr Farron said: "Labour peers are holding the democratic process hostage by blocking any progress of the Parliamentary Voting System and Constituencies Bill.
"Ed Miliband has spoken of a new way of doing politics but the tricks employed by Labour peers are the worst example of petty party politics.
"Their claims of scrutiny are completely undermined by their own pantomime performance in the House. It is time Ed Miliband showed some leadership and took control of his party."