Will a second Scottish independence referendum happen?

Nicola Sturgeon has given the thumbs up to a consultation that could lead to a second independence referendum

Next week the Scottish government will start consulting on a draft bill for a second independence referendum. Here, I reflect on that announcement by Nicola Sturgeon and how it might fit in with her other policy plans.

Preparing for a second referendum on Scottish independence and actually holding one are not the same thing.

To be clear, Nicola Sturgeon is in preparation mode. Keeping an option open, rather than committing to Indyref2 anytime soon.

Her promise to publish a draft referendum bill next week energises the SNP membership.

Ms Sturgeon hopes it will also concentrate minds in the UK government - to head off a possible referendum with further devolution and a Brexit deal that preserves Scottish links with the EU.

Will Indyref2 happen?

The SNP wants Holyrood to have new powers over agriculture and fishing, a say on immigration and the ability to make some international agreements.

It also wants Scotland, if not the whole of the UK, to remain inside the European single market.

Downing Street has made clear that the prime minister is willing to listen to perspectives from all the devolved governments, without making any promises.

The more the SNP asks that are delivered, the less likely Indyref2 during Brexit negotiations becomes.

Nicola Sturgeon's main conference speech is likely to focus on matters such as the health service and education

However, even if none of the SNP's demands are met, another referendum is still not inevitable.

That's because having lost once, Nicola Sturgeon and co. do not want to lose again.

They don't want to call a vote unless they are confident of winning and it would take a further shift in public opinion to convince them of that.

They think that shift could come if Brexit starts to look like a bad deal for Scotland.

However it turns out, the UK's departure from the European Union transforms the Scottish independence question into a choice between two unions - the EU and the UK.

What are Nicola Sturgeon's priorities?

It raises questions - old and new - for supporters of independence to resolve.

Questions over currency, EU membership, low oil prices, access to markets in the rest of the UK and the common travel area.

Brexit also significantly changes the nature of the UK that Scots voted 55% to 45% to remain part of in 2014.

It's for that reason the SNP argue that the independence option - presented as a once in a generation offer two years ago - must remain on the table.

As long as it does, their political rivals say it heaps uncertainty on top of the uncertainty that has already been created by the EU referendum result.

The Conservatives, Labour and the Liberal Democrats also argue that independence distracts SNP ministers from their devolved responsibilities.

Nicola Sturgeon sought to counter that suggestion in her main address to her party's conference on Saturday which focussed on her priorities for services like the NHS, education and the business sector.