Factbox-Scottish election: how it will work and what to watch

Council staff carry ballot boxes and a sign to a van as they prepare to deliver them to polling stations ahead of Scottish parliamentary election held on May 6, at the Royal Mile, Edinburgh, Scotland, Britain, May 4, 2021. REUTERS/Russell Cheyne

EDINBURGH (Reuters) - Scotland is holding a parliamentary election on Thursday that has been transformed into a proxy vote over whether the nation should get another say on whether to leave the United Kingdom.

Scotland's leader, Nicola Sturgeon, has described the election as the most important in the country's history. The outcome could ultimately put Scotland on the path towards breaking its 314-year union with England.