The image of Prime Minister Malcolm Turnbull dropping a $5 note into a homeless man’s empty coffee cup has gone viral, but not for reasons he might have hoped.

Holding a wad of money in his other hand, the PM Labor dubbed ‘Mr Harbourside Mansion’ was criticised by some commentators for not giving the man a higher sum.

But Mr Turnbull’s real mistake, according to a senior Salvation Army official, was giving the man cash in the first place.

“It does potentially send the wrong message,” Major Brendan Nottle told The New Daily, who described the current spike in homelessness in Australian capital cities as a “crisis”.

The City of Melbourne also confirmed it does not recommend giving money directly to the increasing number of people sleeping rough in Australian metropolitan cities.

‘This photo doesn’t even need a caption’

The PM shook the man’s hand after handing him the money. Photo: Daily Mail

Mr Turnbull was on his way to address the Committee for Economic Development of Australia (CEDA) in the Melbourne CBD when he saw the homeless man sitting on the ground with a cardboard sign.

He paused to drop the note in the man’s cup and shake his hand, before heading off to address the CEDA audience.

It was ultimately a bad day for the PM, who was later ambushed by protestors who breached AFP security.

Major Brendan Nottle said giving money to homeless people was not ideal.

“We recommend you go with them to get food or buy them a sandwich. rather than just handing over money,” he said.

https://twitter.com/azzamckazza/status/766046911514095616

Mr Nottle said engaging with the person was the most important thing, to “send a message that they’re human and not a number”.

Guardian columnist Van Badham posted the image, taken by an Australian Associated Press photographer, to her Facebook page, where it ignited fierce debate.

Why does Malcolm Turnbull shake hands with homeless men in front of cameras? #auspol

— Rachel Baker (@RachelBkr) August 17, 2016

https://twitter.com/NoLongerVerbose/status/766460073275039744

Badham drew attention to Mr Turnbull’s other hand, which held a number of $50 and $20 notes.

“Check Malcolm’s right hand, then check his left hand – and you’ll know why this photo doesn’t even need a caption,” she wrote.

The reaction was mixed, with many chastising the former investment banker for not handing over a bigger chunk of his reported $200 million fortune, while others defended Mr Turnbull for simply taking the time to give at all.

Others accused accused the prime minister of staging the photo opportunity.

Oh LOL: 'It was a human reaction': Malcolm Turnbull defends giving money to a beggar – and the photographer just happened to get the shot!

— Schloss Lulzville Schadenfreude (@GeorgeBludger) August 19, 2016

‘I felt sorry for the guy’

When questioned on Melbourne radio station 3AW, Mr Turnbull defended the move.

“I felt sorry for the guy,” he said.

“It was a human reaction and I’m sorry if that has disappointed some people,” Mr Turnbull added.

The City of Melbourne told The New Daily it encouraged people “not to give money directly to people who beg, and to speak to the services about how best to help [homeless people]”.

Homelessness or ‘sleeping rough’ is on the rise in major Australian cities. Photo: Getty

“Begging and homelessness are both extremely complex issues,” the spokesperson said.

Both Major Brendan Nottle and the City of Melbourne confirmed homelessness in Melbourne’s CBD had skyrocketed 74 per cent between 2014 and 2016.

Mr Nottle, a former Melburnian of the year, blamed the closing of a number of caravan parks in Melbourne’s outer suburbs, as well as the pressures of gentrification and property development.

“There is simply a lack of affordable housing,” he said, noting he would like to see Malcolm Turnbull engage in a more bipartisan approach to homelessness prevention.