Mr Blackford today issued a fresh calls for the opposition parties to unite behind a "temporary administration" in order to deliver a Brexit extension beyond October 31.
The prospect of a vote of no confidence in Boris Johnson, which could see him removed from office, floundered this week with the opposition unable to agree on a caretaker replacement.
Labour and the SNP back Mr Corbyn as leader of the official opposition, but this is opposed by the Lib Dems who insist he will not command a Commons majority. Lib Dem Leader Jo Swinson has suggested compromise candidates such as father of the hose Ken Clarke or Labour's Harriet Harman.
But Mr Blackford today called on the opposition majority against No Del to "come together" and find a "way through this crisis."
"All we're talking about, by our constitution, is someone that has to be in place for a few days to create the mechanism for that," he told BBC Radio Scotland's Good Morning Scotland.
"People have got to see that for what it is.
“It’snot about forming a Government, this is not a Government that can achieve a legislative programme.
"It's a mechanism in order to deliver an extension on Article 50 and to call an election. I think we've got to realise the significance of what we're trying to do here.
"If we end up crashing out of the European Union because the Liberal Democrats have not been prepared to remove the Tories from office, then they will pay a price electorally for that, not just in Scotland but throughout the United Kingdom."
Mr Johnson claims he won't seek an extension s despite it being enshrined in law under the so called Benn Act.
Under the arithmetic of the Commons, the united Labour, SNP Lib Dem and smaller party votes would not be enough to secure the majority needed to install Mr Corbyn as PM. At least eight Tory rebels - now sitting as Independents - would be required, which appears a forlorn hope.