David Cameron and Alex Salmond are understood to have agreed that a single "yes or no" question on whether Scotland should leave the United Kingdom will appear on the ballot papers for a independence referendum.
The Prime Minister and the Scottish First Minister will meet in Edinburgh on Monday to finalise arrangements for a vote expected to take place in Scotland in late 2014. The historic agreement is also expected to allow for 16-year-olds to vote in the referendum.
Downing Street last night refused to confirm the timing and location of the meeting, but said that Mr Cameron will meet Mr Salmond "shortly". But Scotland Office minister David Mundell supported reports of the deal, telling Sky News: "Westminster will devolve the power to the Scottish Parliament to hold a single-question referendum on whether Scotland should be in or out of the United Kingdom. We anticipate that happening in autumn 2014."
The announcement came after "substantial progress" was made yesterday in discussions between the Westminster and Holyrood governments over how and when the referendum should be held, after Deputy First Minister Nicola Sturgeon and Scottish Secretary Michael Moore met for talks.
A joint statement issued by the Scottish Government and the Scotland Office after the meeting said: "Further substantial progress towards agreement was reached."