Gordon Brown has revealed plans to rush new tax and welfare powers for Scotland through Westminster before the next election, in an effort to stop Labour voters backing independence.

The former prime minister said Labour wanted draft legislation ready by the end of next January, only four months after the referendum on 18 September, as part of an urgent effort by the no campaign to regain control of the independence debate.

The package is likely to include agreement that Holyrood should set and control a far larger chunk of income tax raised in Scotland, and potentially £1.7bn a year in housing benefits, though Labour is resisting Conservative and Liberal Democrat proposals to hand Scotland total control over its income tax rates.

Plans for a high-speed legislative timetable involving Labour, the Tories and Lib Dems were confirmed by the chancellor, George Osborne, on Sunday after a YouGov poll gave the yes campaign its first lead in the referendum campaign.

The YouGov poll showed a surge in support for independence among Labour voters, with up to 35% now on the brink of handing Alex Salmond's nationalist government and the wider independence movement a shock victory next week.

Speaking before he unveiled the plans at a miners' club near Edinburgh on Monday night, Brown made clear the pro-UK parties now feel under intense pressure to prove they will deliver an alternative offer.

"Quite simply, Scottish voters deserve to know to the fullest extent possible about how new powers as ambitious as possible will be delivered as soon as possible within the UK," he said.

"And so we are demanding a tight timetable with tough deadlines and streamlined procedures.

"A no vote on 18 September will not be an end point, but the starting gun for action on 19 September, when straight away we will kick off a plan to deliver the enhanced devolution that we want."

Senior figures in Labour, the Tories and Lib Dems are now finalising the details of that deal and their formal announcement, expected in Scotland this week in a final effort to halt the late surge in independence support.

Sources close to the talks said Brown was put forward as the best frontman for the cross-party deal because of his stature among Labour voters, but it remains unclear whether the Tories and Lib Dems will endorse Brown's precise timetable.

There was widespread confusion after Osborne seemed to imply on the BBC1 Andrew Marr Show that the UK parties were proposing extra powers which had not yet been revealed.

Salmond reacted on Sunday saying: "This is a ridiculous position being put forward by a campaign in terminal trouble. All that's happening now is that people like George Osborne, David Cameron, Ed Miliband – the whole Westminster elite – are losing the referendum campaign, and the people of Scotland are winning it. We've got them on the run."

Osborne's remarks were later clarified by Alistair Darling, chairman of the pro-UK umbrella group Better Together, who said the chancellor was referring only to a new timetable and procedure for introducing the new powers – the timetable outlined by Brown on Monday. Until now, it had been expected that a cross-party deal on extra powers could take several years before a new bill came to the Commons, but the three parties have been negotiating this faster process for some weeks – before the YouGov poll was released.

Brown said his ultra-fast timetable would start the week after the referendum. His timetable then involved an official government command paper in October, followed by a month's intensive consultation. That would be followed by a government white paper or similar document, with details of which powers the parties agreed on and which were still being debated.

Johann Lamont, the Scottish Labour leader, endorsed Brown's timetable.

"The people of Scotland want certainty on September 18 and thanks to Gordon's plan we will be able to give them certainty that a new plan for devolution will start the day after a No vote in the referendum," she said.

"While the nationalists ask us to take a leap of faith on currency, pensions and funding of our NHS, Scottish Labour will use the strength of the United Kingdom to make Scotland stronger."