Image copyright
Getty Images
The SNP is to decide on a new currency plan for an independent Scotland as its Spring conference opens in Edinburgh,.
The party leadership, including First Minister Nicola Sturgeon, wants Scotland to keep the pound in the years after independence.
They say the country could then look to introduce its own currency if six economic tests are met.
But some activists believe this does not go far enough, and want a separate currency introduced sooner.
The party conference comes in the week Ms Sturgeon laid out her plans for a further referendum on Scottish independence.
She told MSPs she wanted to give people "a choice on independence" before the next Holyrood elections in 2021 if the UK leaves the European Union.
However the UK government said the Scottish Parliament would not be given the power to hold a second poll.
What does the SNP leadership want?
Delegates at the two-day conference in Edinburgh will be asked to back proposals put forward by deputy leader Keith Brown and Finance Secretary Derek Mackay, which are largely based on the SNP's Growth Commission report.
Their motion says that the currency of an independent Scotland "should continue to be the pound sterling" until a separate currency "can be safely and securely established".
The aim should then be for the Scottish Parliament to take a decision on whether to establish a new currency "by the end of the first term of an independent Parliament".
But the motion also says that the precise timescale for doing so should be "guided" by the six tests set out by the Growth Commission.
These tests include an independent Scotland having a "sufficiently strong and credible fiscal position in relation to budget deficit and overall debt" before a separate currency is introduced.
And there would need to be evidence that the new currency would "meet the ongoing needs of Scottish residents and businesses".
Why is this significant?
The policy shift would mark a major change from the SNP's stance ahead of the 2014 independence referendum, when then-first minister Alex Salmond said Scotland would continue to use the pound in a formal UK-wide currency union.
This was immediately ruled out by the UK government - with the resulting uncertainty over what currency an independent Scotland would use widely seen as being a factor in independence being rejected by 55% to 45%.
But not everyone likes the new plan?
The Growth Commission proposals were drawn up by former SNP MSP Andrew Wilson, but have been heavily criticised by some on the left of the party - with former MP George Kerevan among those who want the six economic tests scrapped.
He argues that the leadership's plan is "conservative" and "could leave Scotland using the pound indefinitely".
Mr Kerevan has also claimed that it could "allow the City of London financial institutions to dictate an independent Scotland's decisions" and "effectively negate the very point of seeking independence".
He has been backed by some SNP branches and Inverclyde MP Ronnie Cowan, who have tabled their own plan that would see the party commit to introducing a new currency within the first term of an independent parliament.
Other proposals to be considered by the conference include introducing a separate currency "immediately" after independence, or doing so "as soon as practicable".
So what is likely to happen?
The leadership is confident of getting its own plan approved by the conference on Saturday afternoon, and believes it offers the best chance of converting No voters to the independence cause.
It points to polling which suggests only a small proportion of voters - about 6% - would want to switch to a Scottish currency in the short term.
Writing in the National newspaper earlier this week, Ms Sturgeon said it was not credible to suggest that new financial institutions, such as a central bank, could be set up immediately after independence.
And she said proposing to "press ahead regardless of our state of preparedness or the state of the economy" would "undermine rather than enhance the case for a Yes vote".
Ms Sturgeon will address the conference on Sunday, just days after making her announcement on a second referendum.
She denies that the move was an attempt to placate activists who believe she has been too cautious in her pursuit of independence.
The conference will open on Saturday with a speech by Scotland's Brexit secretary, Mike Russell, who will argue that Scotland is moving "inexorably to independence".
But he will urge delegates to listen to everyone in the country so that they can "play a part in building our new national story".