The Liberal Democrat leader today told his party conference the future of the Union is at stake and insisted it was "imperative" Lib Dems MSPs are elected to Holyrood.
In a speech delivered online due to social distancing restrictions, Sir Ed warned Britain was at risk and vowed to build “a better United Kingdom”.
He said: “Next May, we must get more Liberal Democrats elected to councils across England, to the Assembly in London, to the Senedd in Wales and – crucially – to Parliament in Scotland.
“Elections often determine the future of our country, but these Scottish elections could well determine if our country has a future.
“Once again, the forces of nationalism threaten to tear our family of nations apart.
“So it is imperative that we get brilliant Liberal Democrat MSPs elected to Holyrood in May, to reject more division and instead put forward a positive partnership, to work for Scotland and work for a better United Kingdom.”
Sir Ed was speaking at a time his party has plunged behind the SNP in a UK-wide poll.
A former minister in the coalition, Sir Ed also vowed to be "the voice of nine million carers" as he made his first conference speech since becoming leader.
The Lib Dem leader explained he was driven by his own experiences of caring for his mum and his disabled son.
He said: "John is 12, he can't walk by himself, he was nine when he first managed to say 'Daddy'.
"John needs 24/7 care - and probably always will.
"So let me say this, to all of you who need care. I understand what you're going through and I promise you this - I will be your voice. I will be the voice of the nine million carers in our country."
Sir Ed also sought to reaffirm his pro-EU credentials just days after suggesting on the BBC’s Andrew Marr Show the matter was closed.
He had told the presenter: "People aren't talking about Brexit anymore, they are talking about coronavirus."
Despite this, the Lib Dem leader insisted his party will "always be European".
He explained: “We will always be a proud Liberal party: Defending individuals. Nurturing community. Protecting civil liberties. Championing the environment. Patriotic. Internationalist. And yes, always pro-European.
“But we have endured three deeply disappointing general elections, in five tough years.
“At the national level at least, too many people think we’re out of touch with what they want.
“The answer is to listen to what people are really telling us. And to change.”
Sir Ed also repeated his calls for a public inquiry and accused the UK Government of blaming "anyone, but Boris Johnson".
He explained: “Given the enormity of the threat to our country, it’s with deep regret and sadness that I must say: this Government and this Prime Minister have just not risen to this challenge.
“With unbelievable incompetence, this Conservative Government is failing our people, in one of our darkest hours.”