Boris Johnson has said he is confident he will strike a deal with the EU if Labour continue to resist a general election.
During a visit to Scotland, the prime minister said it was a "sensational paradox" that an opposition party has turned down the chance of going to the electorate.
"Never in history has there been a an opposition party that has been given the chance to have an election and has turned it town.
"If I may say so, I find they're making an extraordinary political mistake, but it is there decision they don't want to have an election, they don't want to move this thing forward, fine we will get a deal on October 17, 18.
"And then we'll come out of the EU but that will be the beginning of the process in which we start a new partnership with our European friends plus we look to new opportunities around the world," he added.
His visit to Scotland came as Labour’s Jeremy Corbyn and other Westminster opposition leaders were holding talks about their approach to the timing of an election.
The prime minister said it "grieved him deeply" to have to remove the whips from Tory MPs but added "to be clear we must get Brexit done".
"It grieved me deeply, these are friends of mine and I worked with them for many years but we have to get Brexit done and we were being very clear about the risks we are running now in snarling up the process leaving the EU in Parliament.
"And yes of course, I am going to reach out to those colleagues and have been reaching out to them and try to find ways of building bridges but I have to be clear we must get Brexit done, that is my message to colleagues let's come together, get this thing over the line and unite out country and get over defeating labour the opposition when they finally have the guts to have an election."
Regarding the split in his party and when asked at what point he might resign, Mr Johnson said: "What I said is that we had to deliver Brexit, unite the country and defeat Jeremy Corbyn, that's what we're going to do.
Asked again at what point he might resign, he said: "Well, I mean, after those three objectives have been accomplished I will... at some point after those three objectives have been accomplished."
Labour, the SNP and Liberal Democrats could refuse to back the PM’s second attempt to get an early election on Monday, because of concerns the poll should be delayed until a Brexit deadline extension has been secured.
The Prime Minister has said he wants polling day to be October 15, but in order to call the snap election he needs a two-thirds majority in the Commons and opposition parties do not trust him to stick to that date.
They also have concerns about whether he will comply with the cross-party legislation due to be passed by the House of Lords on Friday which would require him to seek a delay to Brexit if there is not a deal in place by October 19.
During his first stop in the fishing town just north of Aberdeen, Mr Johnson watched as fishermen landed their catches and brought them into the market to sell, before a short sail around the harbour on a boat named Opportunus.
With pressure mounting on Mr Johnson over Brexit after MPs voted to rule out no-deal, Mr Brerbner said he would urge the PM to get a deal or risk delays to "perishable" fish exports at the border.
"I think it would be good to get a deal, to get a trade deal in place," he said.
"If there’s no trade deal then there’s a lot of uncertainty.
"We’d like to see a deal with Europe, but one that works for both parties and not a one-sided deal.
"It’s a sea of opportunity up here.
"Once we know where we are with Brexit, there is a huge amount of opportunity to recapture the seas and the waters back for the UK."
During his trip to Aberdeenshire, Mr Johnson rejected calls to sack his controversial adviser Dominic Cummings.
Former Tory leader Sir John Major had unleashed a scathing attack on the PM’s aide, branding him “a political anarchist”.
In a speech in Glasgow on Thursday night, Sir John urged the PM to get rid of the “overmighty” Mr Cummings “and do it quickly”.
But when asked if he would now sack his key adviser, Mr Johnson said: “Look, advisers advise and ministers decide.”