With the finishing line of Britain's Brexit election in sight on Thursday, Boris Johnson's mouth had more or less avoided the kind of headline-making gaffes that have partly defined his political career — until four-year-old Jack came along.

To start the week, a photograph of the little boy lying on the floor of a hospital in Leeds waiting to be treated for pneumonia was splashed across the front page of the Daily Mirror. The image instantly became a potent symbol of a health-care system in decay.

But instead of offering a compassionate response, the Conservative leader fumbled during a scrum, doing his best to avoid addressing the issue directly.

He looked the other way, then offered an evasive answer before grabbing a reporter's phone and putting it in his pocket so he wouldn't have to look at Jack's photo.

"He doesn't care," Labour Leader Jeremy Corbyn said later. "It's an example of what's happening in our NHS [National Health Service].

Headline in the Daily Mirror about a four-year-old boy treated on the floor of a hospital in Leeds. Johnson has avoided confronting criticism about the state of the country's public health care system. (Daily Mirror)

Whether that particular moment will haunt Johnson on voting day remains to be seen. What may be more notable is how rare such moments have been for Johnson on the campaign trail.

Johnson's entire career has been punctuated by them.

He has used derogatory slurs to refer to gay people and black people, and notoriously likened the appearance of burka-wearing women to British mailboxes.

His time as Britain's foreign minister was widely seen as a failure, in large part because of impromptu remarks about a British-Iranian woman being held in Iran on charges of espionage.

His false suggestion that Nazanin Zaghari-Ratcliffe was "teaching journalism" in Iran — and wasn't simply a tourist — undercut efforts to free her and she remains in jail to this day.

During this election, however, there have been few big blunders. And, perhaps as a result, polls suggest Johnson is heading into Thursday's vote with a shot at winning the majority he'd need to lead the U.K. out of the European Union his way.

A photo from 1984 featuring the Oxford Union, with Neil Sherlock, front centre, and Boris Johnson, top right. (Neil Sherlock)

"His minders have sought to try to ensure he doesn't make lots of mistakes," said Neil Sherlock, a business consultant and political adviser who has known Johnson since their years together in student politics at Oxford University.

"They want him out there, doing things, but not being questioned too closely."

Old foes

Sherlock, who now campaigns for Britain's Liberal Democrats, actually went head to head with Johnson in 1984 for the job of president of the Oxford Union debating society — and won.

For three decades, he's watched closely as his old foe manoeuvred from a career in journalism to politics, first as an MP in the House of Commons, then mayor of London, cabinet minister and now prime minister.

"I don't think he's particularly changed from the sort of person he was when I first knew him," Sherlock told CBC News in an interview.

"He still really focuses on ... being a performer, using rhetoric and jokes to deflect. And pauses — where he sort of plays with his hair.

"People either love him or hate him."

WATCH | Old Oxford classmate recounts what Boris Johnson was like as student politician:

Neil Sherlock ran against Boris Johnson for student union president at Oxford in the 1980s. Years later, he says Johnson is still the same politician but on a bigger stage. 1:24

An opinion piece in The Times this past weekend put the dual narrative of Britain's relationship with Johnson rather more colourfully:

"They know he's a scoundrel, know he's a cheat, know he's a selfish careerist ... But something about his rascality appeals."

The writer, former Conservative MP Matthew Parris, then added:

"Untruth comes as effortlessly to him as breathing."

Ouch.

Flip-flops

Johnson's flip-flopping has included reversals on everything from Brexit to building a third runway at Heathrow Airport.

Just days ago, the head of Northern Ireland's Democratic Unionist Party, which had supported the Conservatives in government, accused Johnson of "betrayal" for reversing his position on a customs arrangement for Northern Ireland post-Brexit.

British Conservative candidate David Burrowes, right, with Sajid Javid, chancellor of the Exchequer, campaigning Tuesday in Enfield. (Pascal Leblond/CBC)

For Neil Sherlock, the quality in Johnson that overpowered all others back in Oxford — and still does today — is his sense of entitlement and ambition.

"The key thing was holding the job. The key thing for him, probably from Day 1 coming to Oxford, was to be president of the Oxford Union. And I think from Day 1 of being an elected politician he wanted to be prime minister."

"So it's a lot more about the job than perhaps a very detailed view of how he's going to do the job."

This election, Johnson's campaign can probably be reduced to a single sound bite: "Get Brexit done."

WATCH | 'Let's get this done': A look at Boris Johnson's Brexit messaging throughout campaign:

Boris Johnson and the Conservatives have made "get Brexit done" a campaign focus. The National looks at the tactic and whether it will work. 2:21

To literally drive home the point, one of his final electioneering stunts was to drive a backhoe with that phrase fixed on the shovel through a faux brick wall painted with the words: "Gridlock."

Johnson assumed the Conservative leadership, and with it the role of prime minister, last summer, promising to take Britain out of the European Union by mid-October. But time and again, he lost key votes in Parliament after opposition parties formed a united front against both his timetable and the threat of leaving the EU without a deal setting out the terms of separation.

Labour, of course, argues the Tory platform won't bring finality to anything, and that years of negotiations and uncertainty will surely follow as new trade deals are negotiated with Britain's partners.

'Corbyn is dangerous'

Still, the unanimity of opinion polls that put Johnson out in front of the race suggest the "get it done" campaign has helped firm up his position.

CBC News visited the north London riding of Enfield Southgate, which voted "Remain" in the 2016 referendum, but where Brexit fatigue could be giving Conservative candidate David Burrowes a chance.

Johnson walks past a Union Jack-themed bulldozer, with the words 'Get Brexit Done' inside the digger bucket during a general election campaign event in Uttoxeter this week. (Ben Stansall/AFP/Pool via Reuters)

Burrowes represented the working class neighbourhood, known for its Turkish shops and restaurants, for 12 years as the MP before Labour won the seat in an upset in 2017.

On the doorsteps, Brexit is top of mind for voters. And whatever Johnson's faults, Burrowes says, he's seen as a more capable leader than Jeremy Corbyn.

"Whatever you think about his foibles, the difference between him and Corbyn — Corbyn is dangerous. The fact he's going to wreck our economy," said Burrowes.

Labour's platform, which appears particularly popular with younger voters, calls for a drastic repositioning of Britain's economy, with higher taxes, free university education and re-nationalization of the rail system.

Conservatives claim the proposals would bankrupt the country.

Doorstep support

Among the shops on Enfield's main street is the Cyplon Holidays travel agency, a third-generation business now run by Tass Auastasi.

"I like him," Auastasi said of Johnson. "He reminds me of [U.S. President Donald] Trump. Both are very big characters. I think he will do a good job."

While Auastasi says he voted to stay in the European Union, the uncertainty about what comes next is hurting his business. People are holding off booking holidays because they're concerned about potential visa issues and other changes.

"Brexit has to be done," he said.

Labour Party Leader Jeremy Corbyn meets with volunteers in Glasgow. (Russell Cheyne/Reuters)

Despite his off-colour remarks and tendency to make up policy on the fly, Johnson will provide more certainty for business than Labour can, Auastasi said.

"He's just human. He's normal," he said. "Everyone has done something in the past that may not be seen as right now, but then it was OK."

Majority crucial

With all the opposition parties lining up against Johnson's Brexit plans, a Conservative majority is the only path to having the current exit deal with the EU approved.

And even with favourable polls, Neil Sherlock believes that's far from guaranteed.

"Boris Johnson can be beaten in an election," he said. "People who are saying that [he's] going to have a big majority, well, we shall see. Seat by seat, the battles are often very different."