The Prime Minister put a reporter’s phone in his pocket after he was asked to take a look at the photograph of Jack Williment-Barr, shown covered with coats to keep warm as he waited for a bed at Leeds General Infirmary.
Here are other memorable moments from elections in previous years, from angry hospital confrontations to fields of wheat.
- Jennifer’s Ear
“The War of Jennifer’s Ear” is the moniker for a row raised by Labour and leader Neil Kinnock during a party election broadcast in the 1992 campaign.
Five-year-old Jennifer Bennett had to wait 11 months for surgery to treat “glue ear”, a condition which causes dulled hearing, it was claimed, while another little girl had gone private and was treated without delay.
The next three days were dominated by stories about whether or not the broadcast was a fraud, who leaked information about the girl’s family and not, as Labour had hoped, about general health issues.
It later transpired that Jennifer’s grandfather, a Tory, had informed the Conservatives before the broadcast about what Labour was planning.
- 'Bigoted woman'
It was a notorious encounter known as “bigotgate” when Gordon Brown bumped into lifelong Labour voter Gillian Duffy on the 2010 election campaign trail.
The Rochdale woman, who had popped out for a loaf of bread, heckled the then-prime minister on the issue of immigration while he was being interviewed on live TV.
Mr Brown forgot to remove a microphone from his lapel after being grilled and was overheard dismissing her as a “bigoted woman” – prompting a media frenzy.
- Fields of wheat
Theresa May was asked a question she was clearly not expecting in a 2017 election campaign interview.
ITV’s Julie Etchingham probed the prime minister about the “naughtiest thing” she had ever done just days before the public went to the polls.
Mrs May’s confession was not quite what viewers might have expected, revealing: “I have to confess, when me and my friend used to run through the fields of wheat – the farmers weren’t too pleased about that.”
It prompted political figures from across the spectrum revealing their “naughtiest” pursuits.
- Prescott’s punch
It was more than a verbal punch-up when cabinet minister John Prescott was egged during a visit to Rhyl in 2001.
Lord Prescott punched Craig Evans after being splatted by the farm worker, launching a confrontation that was captured by broadcasters and photographers.
It became the most talked-about event of the campaign trail and distracted attention away from Labour’s manifesto launch.
Lord Prescott always insisted that he was acting in self-defence when he landed the punch on Mr Evans after he felt a blow to the head, which was caused by the egg.
- Hospital confrontations
In the same 2001 campaign, Tony Blair was subject to a tense encounter on live TV with the angry partner of a critically-ill cancer patient.
Outside Queen Elizabeth Hospital in Birmingham, Sharron Storer told Mr Blair that Labour had failed the NHS and her partner, repeatedly shouting down the prime minister as he tried to respond to her allegations.
She complained that partner Keith Sedgwick had been forced to wait in the hospital’s casualty department because there was no specialist bed available for him.
- 14 pints a day
Conservative leader William Hague revealed in an interview with GQ magazine that he used to drink up to 14 pints of beer a day when he was a teenager.
He was criticised for the claims during the 2001 election campaign, with the charity Alcohol Concern at the time saying it “certainly wouldn’t recommend” anyone drinking at that level.