SNP Westminster leader has claimed there's an "unstoppable" desire for independence in Scotland, and that it must not be blocked by the next Prime Minister, as he urged Labour and Liberal Democrat voters to "lend" the SNP their votes.
Mr Blackford claimed the SNP was the main challenger in every Tory seat in Scotland, as support for Labour had "collapsed" and the Liberal Democrats were "too weak" to take on the Conservatives.
Pointing to three council by-elections this week - Rosyth, Dunfermline Central and Inverness Central, which were all won by the nationalists with the Tories second - and a YouGov poll which put Jeremy Corbyn's party on just 12 per cent, he said the SNP was now the "only party that can deprive Boris Johnson of the majority he craves - and lock the Tories out of government".
He added: "This is one of the most important elections in Scotland’s history. As recent election results and polls have shown, Labour and the Lib Dems are too weak to take the Tories on in Scotland. The SNP is by far the strongest Remain party, the only party that can beat the Tories, and the only party offering people in Scotland a choice over our future.
"My message to people across Scotland who have previously voted Labour or Lib Dem is lend your votes to the SNP at this crucial election - so we can defeat the Tories, ensure Scotland has a choice over our future, and remain at the heart of the EU."
The party's Westminster leader also argued that to refuse Scotland the power to hold another independence referendum would be undemocratic if the SNP wins the most seats in the looming General Election.
Speaking on the BBC's Andrew Marr Show, Mr Blackford claimed that a "move towards independence is unstoppable, it will not change whether there is a Corbyn or a Johnson government in London."
"Our priorities, principally, in this election is about making sure we can escape Brexit - that's the first thing - but also securing Scotland's right to choose its own future", Mr Blackford said when asked about forming potential coalitions with other parties.
On the issue of securing powers to hold another Scottish independence referendum, he said: "It doesn't matter if it's Jeremy Corbyn or if its anyone else, whoever is Prime Minister has got to respect democracy and the simple fact of the matter is the SNP won the election to the Scottish Parliament in 2016 on a manifesto commitment of a referendum if there was a change of circumstances."
Warning the Tories and Labour to not block another independence vote, he added that if the SNP wins a majority of Scottish seats on a commitment to hold another vote, "it will ill-behold any prime minister to stand in the face of democracy and the right of Scots to choose."
Mr Blackford also sought to blame Tory austerity for one in four people - approximately one million people - living in poverty in Scotland, calling for a commission to look at how to tackle the issue of inequality across the UK.
Asked about SNP leader Nicola Sturgeon not being included in televised debates on ITV featuring the Labour and Conservative leaders, Mr Blackford confirmed the party would be taking legal action against the broadcaster.
Referencing his party's previous position as third-largest in Westminster by seats and their 12 years in government in Scotland, Mr Blackford described the SNP's exclusion from the head-to-head debates as "grossly unfair", adding that they would be in court on Monday to challenge the decision.
"We've got to recognise that the public take their view from these debates. Many people will make their minds up based on those debates and there has to be an issue of fairness - not just for us, but the other parties need to be represented in that debate," he said.