The prospect of Boris Johnson as Prime Minister, supported by Nigel Farage, is a "deadly serious possibility" and would represent a "nightmare" for Scotland, Nicola Sturgeon has said.

Speaking at the launch of the SNP's European election manifesto in Glasgow on Friday, the First Minister said that Scotland must be allowed to keep its options open in the face of a potential hard Brexit.

Sturgeon also said that there is now an obligation on her party to provide a "beacon of light and hope" ahead of voters going to the ballot box next week.

"Senior Tories are now openly calling for an electoral pact at the next Westminster election with Nigel Farage," she said.

"Even a few months ago the idea of a Boris Johnson premiership, supported by Nigel Farage, would have been dismissed as a joke.

READ MORE: Nicola Sturgeon: Scots Tories 'terrified' of Boris Johnson leadership bid

"It is no longer funny. It is a deadly serious possibility and for Scotland it would be a nightmare.

"It demonstrates why we must – absolutely must – have all of our options open at this critical time.

"The future of our country is at stake. So, faced with Brexit – and very possibly an extreme Farage-Johnson style Brexit – people in Scotland deserve the right to decide whether Scotland should become an independent member of the EU instead."

The First Minister continued: "Whatever people's views on independence, or whether indeed people voted Remain or Leave, one thing is clear and beyond doubt: Westminster is failing all of us.

"On that I suspect almost everyone in Scotland would agree. So we have the opportunity to send a message to the Tories and to the other Westminster parties that the Brexit chaos has to stop.

"The fact is, Westminster politics is in a pretty dark place right now. That places an obligation on the SNP. Our obligation is to provide a beacon of light and hope."

READ MORE: Tory-Labour talks collapse as Theresa May clings to power

Speaking alongside the party's European election candidates, Sturgeon said that the party's manifesto outlines its commitment to European values.

And the First Minister said that a vote for the SNP next week is a vote to stop Brexit, and would send a clear message that Scotland's voice must be heard.

"This SNP manifesto sets out a positive, progressive, European future for Scotland," she continued.

"It makes clear our determination to stay in the EU. It sets out how we will stand up for Scotland in Europe and be champions of the ideals and values that underpin the European Union.

"Demonstrating our commitment to being a welcoming nation is a core part of the SNP's values.

"We champion internationalism. We believe in co-operation, respect for human dignity and human rights, freedom, democracy, equality and the rule of law.

"These are the core values of the EU. I believe it is right that Scotland should play our full part in promoting those values for the common good.

"And it is more important than ever that we do so now as these values come under attack from the forces of intolerance and extremism.

"So it is not just the economic benefits of EU membership that are important – although they are very substantial.

"It is also the spirit of solidarity and co-operation among equal, independent partners.

"At this election we can send the powerful message that Scotland is for Europe. We can stand up for Scotland's right to be heard and we can proclaim our determination to remain a European nation."