Deputy Prime Minister Nick Clegg's speech will focus on the economic, legal, scientific and sporting achievements of Scotland as part of the UK.
"Over the last three centuries, we've worked together, lived together and faced the world together. " He is expected to say tomorrow in his speech.
"We've created some of the most respected and enduring institutions in the world - our welfare state, the Royal Society and Edinburgh Festival.
"And whether it's Adam Smith laying the foundations of our modern economy; our lawyers leading on the drafting of the Universal Declaration of Human Rights; our scientists working together to discover life-saving drugs like penicillin; again and again, we've blazed a trail."