Boris Johnson has been dubbed "the last prime minister of the United Kingdom" as he urged the EU to rethink its opposition to negotiating a new agreement on the withdrawal agreement.
The Tory Party leader took to the dispatch box for the first time since took office yesterday afternoon.
In a feisty affair in the House of Commons, the SNP Westminster leader Ian Blackford congratulated him by saying: "I should welcome the prime minster to his place, the last prime minister of the United Kingdom".
The comment was greeted with cheers and clapping by his fellow SNP MPs.
He added: "It's often said the Prime Minister lives in a parallel universe - that's been proven beyond any reasonable doubt this morning."
Blackford called on Johnson to hold a general election, a suggestion to which Johnson replied: "The people of this country have voted in 2015, 2016, 2017 - what they want to see is this Parliament delivering on the mandate they give us, including him."
Johnson accused Blackford of "defeatism and pessimism" over the UK, adding: "If we can deliver a fantastic, sensible and progressive Brexit, which I believe we can, and the whole United Kingdom comes out, as I know that it will, what happens then to the arguments of the Scottish National Party?
"Will they seriously continue to say Scotland must join the euro? Will they seriously suggest that Scotland must submit to the entire panoply of EU law?"
The exchange came after BoJo reaffirmed his determination to deliver Brexit by the October 31 deadline, warning of a "catastrophic" loss of confidence in the UK's democracy if they failed.
Johnson, who entered the Commons chamber to cheers from Tory MPs, insisted that he wanted to take Britain out of the EU with a deal.
But he said Theresa May's deal had been rejected three times by the House and could not be brought back again.
"I would prefer us to leave the EU with a deal - I would much prefer it," he said.
"I believe that it is possible even at this late stage and I will work flat out to make it happen.
"But certain things need to be clear. The Withdrawal Agreement negotiated by my predecessor has been three times rejected by this House.
"Its terms are unacceptable to this Parliament and this country," he said.
He said that his new Government was ready to negotiate with Brussels in good faith.
"We will throw ourselves into these negotiations with the greatest energy and determination and in a spirit of friendship," he said.
But at the same time he promise to "turbocharge" preparations for a no-deal Brexit in the event that they were unable to come to an agreement with the EU.
