David Cameron has admitted he "contemplated having to go" if Scotland voted for independence.
The Prime Minister said he would have been "heartbroken" by the break-up of the UK and considered his position when polls put the Yes campaign ahead just days before the referendum.
Alex Salmond will return to Holyrood today for the first time since his bid for Scottish independence failed.
Mr Salmond, who has announced his intention to step down as First Minister, is expected to reflect on the independence referendum and put pressure on the victorious unionist parties to deliver on their devolution pledges in a statement to the Scottish Parliament.
Presiding Officer Tricia Marwick will open today's proceedings with "time for reflection", a Holyrood slot normally reserved for spiritual or philosophical contributions from religious or secular figureheads.
Mr Salmond's statement will be followed by two days of debate on the future of Scotland, with Labour leader Johann Lamont, Conservative leader Ruth Davidson and Liberal Democrat leader Willie Rennie expected to open with responses from the Scottish opposition parties.
Scotland voted against independence by a majority of 55% in the referendum on Thursday.
The woman expected to replace Salmond said she will "follow the mood of the people" if promises made in the run up to the vote are not met.
The double Grand Slam winner said he did not regret giving his opinion, but was 'disappointed' at the way he went about it.
Alex Salmond has announced his intention to end a 24-year career at the forefront of Scottish politics. Here is a brief look at his career.