WILLIE Rennie will today claim that the Liberal Democrats are the progressive, optimistic and outward-looking alternative to the Tories and the SNP, whom he brands the “terrible twins of division”.

The Scottish party leader in his keynote speech to conference will accuse the Conservatives of causing splits between Scotland and England for party advantage while the Nationalists, he will say, are only interested in a new drive towards a second independence referendum.

“It is an alarm that should sound across the whole of Britain,” the Fife MSP will declare. “With the blow of Brexit and the threat of another Scottish independence referendum it means that divisive constitutional politics remain at the centre of our national debate.

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“It is a dismal scene that has been visited upon us by the Conservatives and the SNP. Our future will be a divided one if we leave it to the Tories and the Nationalists; the terrible twins of divisive politics.”

Mr Rennie will claim Theresa May’s Tories and Nicola Sturgeon’s Nationalists have much in common and a shared interest.

“The Tories need Nationalists to scare voters in England; the Nationalists need the Tories to scare voters in Scotland. It’s a campaign based on fear, not hope,” he will argue.

“If we leave progressive politics to the SNP, then that will fail. If we leave the campaign for Scotland's place in the United Kingdom to the Conservatives, it will fail too. That is why we need the Liberal Democrats: progressive; optimistic; outward-looking.”

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He will say: “Our progressive alternative to the terrible twins of division is what our country needs. Progressive, optimistic and outward-looking in Scotland and the whole of the United Kingdom.”

Mr Rennie will also tell the party conference how the Liberal Democrats gained seats from the SNP in May; including his own in North East Fife.

And he will restate the party’s core commitments on mental health, transformative investment in education, protecting liberties and tackling climate change.