Scottish first minister Nicola Sturgeon on March 13, 2017 demanded a new independence referendum to be held in late 2018 or early 2019.
This is once the terms of Britain's exit from the European Union have become clearer.
A vote that could rip apart the United Kingdom just months before Brexit adds a tumultuous twist and highly uncertain consequences to the two-year process of leaving the EU after more than four decades.
PM Theresa May is poised to launch the Brexit process, something opposed by most Scots in last June's vote on leaving the bloc.
Ultimately it is the UK parliament in Westminster–where May commands a majority–which makes the call on whether Scotland can hold a second referendum.
Sturgeon has previously said she wanted Scotland to be allowed to strike its own deal with the EU to keep access to the bloc's tariff-free single market.
The results of the June 23 Brexit referendum called the future of the UK into question because England and Wales voted to leave the EU but Scotland and Northern Ireland voted to stay, with an overall 55 percent in favour of leaving.
Scots rejected independence by 55-45 percent in a referendum in September 2014, though the vote energised Scottish politics and support for the SNP has surged since then.
