The Supreme Court will deliver its judgement next Wednesday on whether the Scottish Parliament can hold a second independence referendum without Westminster's approval.
The UK's highest court heard arguments in the case last month.
The Scottish Government said a referendum would fall within devolved powers, but the UK Government said it was a reserved matter.
Scotland's lord advocate, Dorothy Bain KC, referred the case to the Supreme Court due to uncertainty over whether Holyrood could legislate for a second independence referendum while this was opposed at Westminster.
The judgement on Holyrood's proposed Scottish Independence Referendum Bill will come six weeks after the two-day hearing in October.
The Supreme Court's senior judge, Lord Reed, warned at the time that it could be "some months" before a ruling is reached in the case.
Tip of the iceberg
He said the arguments heard in court were just the "tip of the iceberg", with more than 8,000 pages of written material to consider.
Ms Bain, the Scottish Government's top law officer, argued that a referendum would be "advisory" and would have no legal effect on the Union.
She told the court that, while Scottish ministers might have the "subjective intention" of independence, the bill itself would be objectively neutral.
But Sir James Eadie KC, the UK Government's independent barrister on legal issues of national importance, said it was "obvious" that the bill related to reserved matters and the Union.
He said that meant it would fall outside of the competence of the Scottish Parliament, and argued that the Supreme Court should not rule on the case.
The BBC says that, when Scotland held an independence referendum in September 2014, voters backed staying in the UK by 55% to 45%.
Repeated attempts
First Minister Nicola Sturgeon has made repeated attempts to push for another vote, but there has been no agreement with the UK Government.
In June, Ms Sturgeon unveiled what she called a "refreshed" case for independence and said her government had an "indisputable mandate" for a second referendum, which she wants to hold on October 19, 2023.
But, if the Supreme Court ruling goes against her, she has said she would use the next election as a "de facto referendum" and attempt to use the result to trigger independence negotiations.
Prime Minister Rishi Sunak has given no indication that he is likely to grant formal consent for a second vote.