Tony Blair has said the case for Scottish independence is "much more credible" after the Brexit vote.
The former British prime minister warned the break-up of the UK is now "back on the table" but said he does not want Scotland to become independent.
In a speech in London for Open Britain, which is campaigning against a so-called "hard Brexit" outside the European single market, Mr Blair called on pro-Europeans to "rise up" and persuade Leave voters to change their minds in the face of a Conservative government pursuing "Brexit at any cost".
"The people voted without knowledge of the true terms of Brexit," Blair said. "As these terms become clear, it is their right to change their mind. Our mission is to persuade them to do so."
He said: "In addition to all this, there is the possibility of the break-up of the UK, narrowly avoided by the result of the Scottish referendum, but now back on the table, but this time with a context much more credible for the independence case."
Questioned following the speech, he added: "I want Scotland to remain in the UK. Even if Brexit goes ahead, I'm still in favour of Scotland remaining in the UK.
"Let's be very clear, Scotland's single market with England is of far greater importance to it economically than Scotland's interaction with the rest of Europe.
"When myself and John Major warned this would be a threat to the UK we meant it, and it was true, and you can see that by the referendum coming back on the agenda."
Scottish First Minister Nicola Sturgeon has said another independence referendum is "almost inevitable" in the event of a hard Brexit.
The SNP argues since a majority in Scotland voted to Remain, this represents a material change in circumstances sufficient to make the case for a second independence vote.
Scottish Liberal Democrat leader Willie Rennie said: "Tony Blair is right about Europe but wrong about independence.
"The Conservatives' hard Brexit is bad for Britain's economy, which is why the public need the final say on the deal.
"But Tony Blair is wrong about independence. The case for independence is weaker, not stronger, now, especially with the £15 billion black hole in the Scottish public finances that would hit our NHS and schools."