Boris Johnson has today started a blitz of Labour's heartlands in the North in a bid to convince Leave voters that Jeremy Corbyn's Brexit position is akin to a "great betrayal".
The Prime Minister will spend the three days before polls open targeting voters in traditional Labour strongholds, which his party views as key to securing a Conservative majority.
In a bid to help crack the so-called "red wall" of Labour seats across the North of England, the Conservative Party leader will spend Monday in the Leave-voting regions of the Humber and Wearside.
The PM will blast Mr Corbyn for sticking "two fingers up to the public" on Brexit during his tour of Labour seats.
Places like Grimsby, where the PM visited a fish market in the early hours today, have not been held by a Tory MPs since the Second World War.
Mr Johnson insisted he is "taking nothing for granted" as he launched his final election campaign push in Grimsby at a fish market.
The Conservative Party leader was greeted with cheers and some jokey shouts - along with the smell of fish.
One worker shouted "Boo Boris" while another man could be heard saying: "He brings them out, eh? Phoney b*******."
Mr Johnson posed for selfies and watched a fish auction as cod and haddock were sold.
He was given the task of placing labels on sold items.
Chatting to workers in the market, Mr Johnson asked: "Are you worried about the Dutch super trawlers?"
The PM was told people are concerned, before he asked: "What's that one in the Channel, that huge one they had in the Channel?"
He referred to it as a "mega trawler" and also said: "It was sort of hoovering everything up from the sea then.
"How can they check which fish they're getting? They're just going to take everything on, clean out the seabed, that's the problem."
"Ask the Dutch," came the reply.
The Prime Minister later held a cod in his arms for the cameras.
Mr Johnson also pulled a box of fish across the warehouse floor, prompting shouts of "Go on Boris" from onlookers.
Speaking to broadcasters, Mr Johnson was asked how confident he was he could scale the "red wall" of Labour as he bids to secure a parliamentary majority - something the polls suggest he is on course to achieve.
He replied: "We're taking nothing for granted, we're working very, very hard across the whole country and I think it's a message of unity of bringing this amazing United Kingdom together.
"If we can get Brexit done then we can move forward with investments in infrastructure, education and technology that will unleash opportunity across the whole country.
"It's a message that makes sense whether you're working in the arts and financial services in London or fishing in Grimsby or the arts and financial services in Grimsby."
Mr Johnson is also due to visit Sunderland today and he said Brexit's "roar" was heard for the first time on referendum night after the city's quick count showed a huge swing towards Leave - the PM will tell North East voters that it is Labour that has "let you down most of all" on Brexit.
"It's been the great betrayal, orchestrated from Islington by politicians who sneer at your values and ignore your votes," he will say.
It comes as the former Vote Leave figurehead's pledges on Brexit were brought into question after a second leak poured doubt on the country's ability to be ready to exit the European Union within a year.
If the Conservatives win Great Grimsby from Labour’s Mel Onn this week, it will bring to an end a period of Labour representation in the constituency that has lasted without a break for 74 years.
It will also symbolise how successful the Tories have been at this election in overturning generations of political tradition in Labour's heartlands.
Only four MPs have represented Great Grimsby since the end of the Second World War, all of them Labour - Kenneth Younger, Tony Crosland, Austin Mitchell and Ms Onn.
But it has been a marginal seat ahead of various elections, including 1964, 1987 and 2015, but on each occasion Labour held on.
Now that might be about to change.
The Conservatives need a swing of 3.7 per cent on December 12 to overturn Ms Onn's majority of 2,565.
Polls suggest the party might be on course to take the seat with candidate Lia Nici, and by a comfortable margin.
It is an outcome that could be repeated in other constituencies across northern England with decades of Labour history.
Examples include Bishop Auckland (Labour since 1935), Wakefield (1932), Don Valley (1922) and Rother Valley (1918).
All of these seats could turn blue on December 12 if the Conservatives perform strongly.
If Mr Johnson’s party wins those seats this week, it will vindicate the Tories' strategy of targeting Leave-backing Labour voters in parts of the country that have not seen Conservative MPs for generations.
Six candidates are standing in Great Grimsby: Labour, Conservative, Liberal Democrat, Green, the Brexit Party and an Independent.