Almost 4.3 million people are registered to vote in the Scottish independence referendum, making it the largest electorate ever for a ballot in Scotland.

The 4,285,323 voters include 789,024 people who have applied for a postal vote, which is also the largest volume of registration for postal votes ever in Scotland.

Chief Counting Officer (CCO) Mary Pitcaithly said: "I want everyone's vote to count, whether they are voting by post or in person at a polling place on September 18.

"It's vital that everyone takes great care when completing their ballot paper. Mistakes mean that a ballot paper may not be counted."

Across Scotland, there are 2,608 polling places with a total of 5,579 polling stations. In most areas, a maximum of 800 voters have been allocated to each polling station.

Measures including extra staff at peak times have been put in place to reduce the risk of queues.

Ms Pitcaithly added: "People who are voting at a polling place should think about what time they are going to vote.

"Polling places are busiest during the early morning and in the evening as people vote on their way to and from work. If you are able to avoid these times I would encourage you to do so, to ensure everyone can vote without having to queue for any length of time."

Andy O'Neill, head of the Scotland Office at the Electoral Commission, said: "We welcome this increase in the number of people registered to take part at the referendum. It's now important that voters, particularly first-time ones, take a couple of minutes to read our impartial guide to help them plan when they will cast their vote and ensure it will be counted by correctly marking their choice with a 'X'."

Meanwhile, a poll of almost 9,000 Unite members in Scotland has revealed that about nine in 10 will be voting in the referendum.

A total of 93 per cent of the trade union's members polled said they would be voting, with 92 per cent of male members and 96 per cent of female members stating they would take part next week.

Of those, 88 per cent of male Unite members have made up their minds about how they will vote, compared with 86 per cent of Unite's women members.

The union has taken a neutral position on the vote, and did not canvass workers on how they intended to vote.

Pat Rafferty, Unite's Scottish regional secretary, said: "Working people across Scotland look set to shape the outcome of next Thursday's historic vote by participating in astonishing numbers.

"Our members - the majority of whom are in work as well as sizeable numbers of community members - are fully engaged with the referendum debate on Scotland's future.

"Unite members told us very clearly that they do not want their union taking a stance one way or another, but instead wanted us to help them find the information that they needed in order to make up their minds, which is why this union has been striving to help our members in their deliberations, holding meetings across the ­country to allow our communities to debate the profound decision before us."