Scotland has been promised a Home Rule Bill within 100 days - if the British Labour Party wins May's General Election.
Ed Miliband's trying to shore up support for his party in Scotland - amid concerns it could lose multiple seats to the SNP.
Conservative peer Lord Ashcroft is carrying out regular opinion polls ahead of the election.
He says all the main parties would be foolish to underestimate what the SNP might achieve.
Following Scotland's rejection of independence, former prime minister Gordon Brown set out his vision for the country in a speech last year.
Mr Brown's intervention in the campaign has been credited with helping to secure a No vote.
Politicians on both sides of the debate considered the implications of the vote, with Tory backbenchers saying any further devolution of powers to Scotland must be matched by change in England.
At the time, Labour leader Ed Miliband said the result of the referendum should not be used "for narrow party political advantage".
He backed the timetable of devolution of powers set out by Mr Brown, but said there should be an examination of the wider changes needed to reform UK government.