Image copyright EPA Image caption Supporters of independence have been hoping for a new referendum since 2014

First Minister Nicola Sturgeon says she still wants to hold a Scottish independence referendum in 2020, but has urged "patience" from her supporters.

With the UK government still refusing to agree to a vote, is it likely to happen any time soon?

Why is Scottish independence back in the spotlight?

Scotland held an independence referendum in September 2014, with the No campaign winning 55% of the votes.

But then, in 2016, Brexit happened. Voters in Scotland backed Remain by 62% - but those across the UK as a whole voted Leave by 52%.

The SNP saw this as a "material change in circumstances" which would justify a second independence ballot, because Scotland faced being taken out of the EU "against its will".

And the party has since performed strongly in elections. It won 48 of the 59 seats north of the border in last month's general election, while campaigning to "put Scotland's future in Scotland's hands".

MSPs at the Scottish Parliament have also endorsed the idea of a new referendum, giving Ms Sturgeon what she calls a "cast-iron mandate".

Scotland After 59 of 59 seats Scottish National Party SNP 48 seats , +13 seats compared to 2017

Conservative CON 6 seats , -7 seats compared to 2017

Liberal Democrat LD 4 seats , +0 seats compared to 2017

Labour LAB 1 seats , -6 seats compared to 2017

What does Nicola Sturgeon want to happen?

The SNP leader wants to hold a ballot later this year, and she wants the UK government to agree a transfer of powers for this - as happened in 2014.

This is because she wants the result of any vote to be seen as legal and legitimate - particularly by the likes of the EU, which she would like to see Scotland rejoin.

However, UK ministers have rejected doing a deal - Prime Minister Boris Johnson says the 2014 vote was a "once in a generation" event.

This has raised questions about what Ms Sturgeon can do to turn her pledge of a 2020 referendum into reality.

Does Scotland have the power to hold a referendum?

There has long been legal debate over whether the Scottish Parliament, rather than MPs at Westminster, could pass the laws needed for a new vote on independence to be held - but the matter has never been tested in court.

Ms Sturgeon has rejected holding an "illegal or wildcat referendum", like that held in Catalonia in 2017, but she hasn't ruled out a legal challenge to see if Holyrood could actually legislate for a poll.

But this is not her focus for now. She warns that the outcome of such a court case would be deeply uncertain - "it could move us forward, but equally it could set us back".

Image copyright PA Media Image caption Boris Johnson and Nicola Sturgeon do not see eye to eye on Brexit or independence

So what will Nicola Sturgeon do now?

The first minister says Mr Johnson's position is unsustainable, and is focused on building a political campaign to overcome it.

The SNP is doubling its campaign spending, the first minister is setting up a new "constitutional convention" to win over civic Scotland, and a series of papers detailing how Scotland could become independent will be published.

Ms Sturgeon has also reversed her refusal to let the Electoral Commission re-test the Yes-No question asked in 2014, and that work will now go ahead.

But without an agreement with Westminster, a vote still looks deeply unlikely this year. This means Ms Sturgeon will be looking ahead to the Scottish Parliament elections in 2021, targeting a big win on an explicit platform of demanding a referendum.

Would Scots vote for independence?

This is the big question - after all Nicola Sturgeon doesn't just want to hold a referendum, she wants to win one.

Polling data collected by What Scotland Thinks suggests an increase in support for independence, but it remains very much on a knife-edge.

Image copyright Getty Images Image caption The SNP wants Scotland back in the EU as quickly as possible

Excluding "don't knows", the average of polls in 2019 was 51% No to 49% Yes. The average for 2018 was 55% to 45% - the same as the 2014 referendum. Some polls now even put the Yes side ahead.

The SNP hopes that a combination of Brexit and hostility within Scotland to Mr Johnson's refusals will push the dial further in its direction.

Could an independent Scotland stay in the EU?

In practice, Scotland would not become independent the day after a Yes vote - there would have to be a period of transition. In 2014, the pro-independence side said it would take 18 months to set up an independent Scottish state.

Even if a referendum was held tomorrow, the transition would therefore run beyond the end of 2020 - when the UK is due to complete its exit from the EU.

This means Scotland is leaving the EU with the rest of the UK, and would need to apply to join again.

Scottish ministers accept they would have to go through an "accession process" for EU membership, but want to start this "as soon as possible".

What would it take for Scotland to rejoin the EU?

Scotland would have to meet the same accession criteria as any state seeking to join the EU, although it would have the advantage of having recently been a member.

While many of Scotland's laws and regulations already match EU standards, the entry rules throw up a whole series of questions about things like currency, deficit levels and borders.

Ms Sturgeon has been pressed on many of these topics already, arguing that Scotland could initially continue to use the pound and would not need to join the euro. She says the country's financial position could be brought within EU rules by growing the economy.

However, her own party's prospectus for independence suggests this could take several years, whereas she wants to rejoin the EU as quickly as possible.

The first minister also wants to avoid a hard border between Scotland and England.

She has said answers about this and a whole range of other questions will be set out in detail ahead of any vote.