Boris Johnson is touring Brexit-voting Labour-held seats in Humberside and north-east England, with three days to go before polling day.
In a speech later in Sunderland – 61% of which voted to Leave – the PM is expected to tell voters: “The Labour party has let you down.”
He will attack Parliament, saying it has “delayed” and “denied” Brexit.
Mr Johnson will also travel to south-west England, where he will warn against voting for the pro-EU Lib Dems.
Meanwhile, shadow chancellor John McDonnell will set out Labour plans to deliver a budget to “end austerity” within its first 100 days if the party wins Thursday’s election.
In a speech in London setting out his priorities, he will also pledge to get “money moving out of Whitehall and the City”.
The Liberal Democrats are, meanwhile, pledging to table legislation to stop Brexit immediately after the election by introducing two draft bills they say would pave the way for another EU referendum.
The first would enable the Electoral Commission to start the necessary consultation around a referendum question and lead campaign designation – and the second would provide a referendum on the government’s Brexit deal versus remaining in the EU.
Lib Dem leader Jo Swinson told Radio 4’s Today the “most likely way” to stop Brexit was through another vote as the possibility of her party winning power on its own and revoking Article 50 looked increasingly remote.
The Conservative Party says the prime minister is intending to “visit every region in England and Wales” in the final three days, with a message that a vote for his party is a vote to “get Brexit done and unleash Britain’s potential”.
He started the day at a fish market in Grimsby, one of a number of longstanding Labour constituencies that voted heavily to leave the EU in the 2016 referendum that both the Conservatives and the Brexit Party are targeting.
On a visit to Sunderland later, Mr Johnson is expected to say: “It’s now been 1,264 days since Sunderland’s roar was heard on the night of 23 June 2016.
“1,264 days in which parliament should have delivered what you voted for, taken us out of the EU, and addressed all the reasons you voted so decisively for change.”
He will attack Parliament, saying that it has “bent every rule and broken every convention as it has delayed, diluted and denied Brexit”.
And he will suggest that Mr Corbyn, who is promising another Brexit referendum within six months if he wins power, has “let down” traditional Labour supporters,
“Under Jeremy Corbyn, they promised to honour the result of the referendum – before voting against Brexit every chance they had,” he will say.
Mr Johnson has repeatedly warned that the only alternative to a Conservative majority is a hung Parliament, with Mr Corbyn and SNP leader Nicola Sturgeon forming a coalition and resulting in further referendums on Brexit and Scottish independence.
Ms Sturgeon has said she is confident an agreement on a second independence vote could be done if Labour needed SNP support to form a government if there is a hung parliament.
But Mr Corbyn has ruled out supporting a Scottish independence referendum until after the next Holyrood election in 2021.
On Sunday, Mr Johnson insisted there will not be any checks for goods travelling from Northern Ireland to Great Britain under his Brexit deal.
He told Sky News that a leaked Treasury analysis document was “wrong” to suggest this would be the case.
His Brexit deal means there will be goods checks from GB to NI, but there has been confusion on whether there will be checks in the other direction. Labour said the PM’s claims about his deal with the EU were “fraudulent”.
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