By the close of play today, the Scottish Tories will have a new leader and the party’s days in its current form may be numbered, but this could be decided by as few as 5000 voters.

If the forecasts from the rival camps are correct, turnout at between 55% and 65% will be well down on the 80% across the UK who voted for David Cameron to lead the Conservative Party.

Murdo Fraser, the current deputy leader of the Scottish Tories, stood on a platform of winding up the party and relaunching it under a new identity as a fresh voice in Scottish centre- right politics.

It was a bold approach and it dominated the leadership debate, but it is one that may have cost him victory, as it gave his opponents a target.

He is unrepentant about the tactic, and is expected to do well in the north.

Mr Fraser could have played it safe, and he probably would have won comfortably, but he wanted a mandate for radical change to create a new party that would be seen as much more identifiably Scottish. He believes this is the best tactic for saving the Union, and he has the most support from MSPs.

The candidate with a fresh face -- but who is not challenging the current structure -- is Ruth Davidson.

She only joined the party in recent years and was elected to Holyrood in May. She was an aide to outgoing leader Annabel Goldie and was believed to have the support of the party hierarchy for her bid, resulting in claims by opponents that she had unfair help from central office with email lists. Ms Davidson will do well in the West of Scotland out- with Glasgow, in Ayrshire and in the Borders, where she has the support of MSPs.

The candidate of the party’s grassroots is Jackson Carlaw, who has made a virtue of his lack of support from Holyrood colleagues. Given the traditionalist nature of the party’s mainly elderly membership, he may well do better than the media have predicted, particularly in Glasgow and the West. The outsider is another arch-Unionist, Margaret Mitchell.

The first candidate to achieve more than 50% wins, but the transfers as bottom candidates drop out will be crucial. The final chance to vote is by noon.

Ballot boxes will be opened in a hotel in Edinburgh’s Grassmarket, and the count should be completed some time between 3pm and 5pm, when the victor will be declared.