Britain's election campaign entered its frenetic final straight Monday with Prime Minister Boris Johnson trying to lock in the votes needed to draw a line under years of arguments and paralysis over European Union membership.

Johnson is hoping Thursday's poll hands his ruling Conservatives the majority needed to push through his EU divorce deal and settle debates over Britain's place in the world.

Parliament has been deadlocked since the last election in 2017 stripped the Conservatives of both their majority and ability to implement the result of the 2016 referendum on EU membership.

The main opposition Labour party leader Jeremy Corbyn is trying to upset the odds and usher in Britain's first leftist government in nine years.

50 years of British elections / © AFP

The veteran socialist has promised to negotiate his own EU withdrawal agreement and then put it up for a vote in a new referendum that could still keep Britain partially tied to Europe -- or cancel Brexit outright.

Opinion polls show the Conservatives maintaining a healthy lead.

But Johnson needs to win at least half of the House of Commons seats because his party has no clear partners among the smaller parties.

Some polls suggest the vote could produce another hung parliament that would extend the political paralysis and further frustrates the business community and Brussels.

"We're taking nothing for granted," Johnson said during a visit to a fish market in the northeastern port of Grimsby.

- 'Red wall' -

Northern England has in recent years borne the brunt the effects of increased global competition, which have hit domestic industries from mining to fishing.

Grimsby is part of a so-called "red wall" that traditionally backs Labour because of its support for trade unions and emphasis on social spending.

The party's would-be finance minister John McDonnell promised Monday to shift wealth from London to the regions in the first 100 days of a Labour-led government.

The issues of Brexit, austerity and the NHS have dominated the election campaign / © POOL/AFP

The deep ideological divide between the two main parties has produced a highly personal campaign that appears to have done little to change the minds of voters who opposed or supported Brexit from the start.

Johnson has faced constant questions over his trustworthiness and Corbyn has been put on the back foot over anti-Semitism within his party.

The British leader "is probably the least-trusted politician people have ever experienced," McDonnell said.

Corbyn's main attack line has been to accuse Johnson of failing to properly fund Britain's cherished state-run National Health Service (NHS).

He brandished the front page of a newspaper at a rally Monday showing the picture of a sick boy lying on the floor of a clinic that apparently had run out of beds.

"This is a disgrace. They need to invest in our public services," Corbyn told supporters in the pro-Labour western city of Bristol.

Johnson appeared flustered when shown the image by a reporter who had it on his phone.

He pocketed the reporter's mobile without looking and promised to "study it later".

The prime minister -- his puffy eyes betraying the wear and tear of a manic five-week long campaign -- apologetically returned it at the end of the interview.

A clip of the exchange soon went viral on social media.

- Late surge? -

Yet Corbyn has shown few signs of being able to mount the late surge that put Labour within a whisker of winning the 2017 election.

Polls show the Conservatives leading by about 10 percentage points.

Pollsters believe Johnson needs to be at least six to eight points clear of Labour to secure a majority.

Corbyn is aiming to upset the odds and usher in the first Labour government for nine years / © AFP

Analysts attribute Corbyn's seeming failings this time around to his initial refusal to support a second Brexit referendum that most Labour voters want.

The century-old party has also been abandoned by prominent members who voiced anguish at the anti-Semitism scandals that have erupted under Corbyn's watch.

But Corbyn told supporters in the pro-Labour western city of Bristol that "many people make up their minds at the last moment" and that he would keep campaigning until Thursday night.