Willie Rennie has set out what he said was the “new case for the United Kingdom” as he pledged to fight to keep Scotland in the UK and the UK in the EU.
The Scottish Liberal Democrat leader told the party’s conference in Perth that Nicola Sturgeon was “determined” to hold an independence referendum.
He argued that the economic case for independence is weaker than in 2014.
But he said the case for the UK should be a “positive, uplifting one”.
And he told delegates that “Britain is full of people who care” and that it was important to focus on the “ties that bind us rather than the differences some would use to divide us”.
Ahead of Mr Rennie’s speech, the conference formally backed calls for the party to be “the voice for the majority in Scotland, who want Scotland inside the UK and the UK in the EU”, and to campaign for re-entry into the EU after Brexit.
Highlighting his own family’s links to different parts of the UK, and to Europe, Mr Rennie told delegates that the constitutional debate was “personal” rather than merely a “dry, dusty debate about government structures”.
He added: “It is about family, community, destiny. I want to bring communities and peoples together, not drive them apart.
“That is why I will oppose erecting a barrier, any barrier, in the heart of my family just like I will oppose erecting a barrier, any barrier, in the heart of the United Kingdom or the European Union.
“Because the United Kingdom is our family. The European Union is our family. And we stand with our family.
“Erecting barriers and division with independence – between us and the people of England, Wales and Northern Ireland – is just as objectionable as the division we are seeing with the people of Europe as a result of Brexit.”
Analysis by Brian Taylor, BBC Scotland political editor
Willie Rennie says that indyref2 is unwanted and unnecessary. Yet his speech was founded upon the presumption that such a ballot is coming reasonably soon.
Perhaps he took his clue from the interview with me in which the first minister agreed that indyref2 was now “all but inevitable”. Or the many other interviews in which she has deployed comparable comments.
Either way, Mr Rennie says his party is ready for the fight. The economic case for independence, he said, is now less impressive, particularly in the light of oil figures.
But, he said, there was an emotional case for the Union too. He, Rennie W, was ready to deploy said argument. It was, he said, about “family, community and destiny”. (Theresa May opted for “solidarity, unity, family.”)
On the subject of the EU, Mr Rennie also anticipates a further referendum. Although he tends to bristle, politely, if one suggests it is a rerun of 23 June.
Mr Rennie said he would always “stand up for our United Kingdom” as an “uplifting, mutually beneficial partnership”.
And looking ahead to a potential second independence referendum, he said the Lib Dems would “lead the way on the kind of campaign for the United Kingdom that we want to see”.
He added: “We know the economic case for independence is weaker than even in 2014, so I will not dwell on that today.
“The new case for the United Kingdom is a positive, uplifting one that focuses on the ties that bind us rather than the differences some would use to divide us.
“It is that emotional case. It is the Liberal case for unity. The compassionate case. It goes to the heart of who we are. Our United Kingdom is an uplifting, mutually beneficial partnership that we should cherish rather than trash.
“So as we head into another referendum the responsibility on liberals is great. We must stand up and be counted for our values. This is a battle of ideas and values, not of identities and flags.”
Delegates debated policies including the UK and Europe and maternal mental health before Mr Rennie’s speech.
The two-day event also heard from MPs Nick Clegg and Alistair Carmichael, who both hit out at the rise of nationalism.
Members have approved policy motions backing moves to cut drug-related deaths including “safe injection facilities” and the “de facto decriminalisation of the possession of drugs for personal use”, and on increasing the speed limit for HGVs.
The party also reaffirmed its backing to the “Frank’s Law” campaign for free dementia care for those aged under 65.
Willie Rennie sets out ‘new case for the UK’}