A rare glimpse of internal debate concerning the federal budget played out on the floor of the House of Commons last week.

Certain discussions are usually had behind closed doors, but in this case a minister and a parliamentary secretary could be seen standing between desks on the government side of the House, engaged in what looked to be a tense conversation.

The discussion apparently concerned the government's affordable-housing policy.

MPs had gathered in the House on Wednesday afternoon to mark the passing of Conservative MP Jim Hillyer. When the House adjourned after brief statements, MPs milled about, a line of well-wishers forming in front of Interim Conservative Leader Rona Ambrose.

Finance Minister Bill Morneau stood near his seat along the government's front bench, in conversation with Adam Vaughan, the Liberal MP from Toronto who is a parliamentary secretary to the prime minister. The two stood a couple of feet apart.

Morneau was stone-faced. Vaughan gestured with his hands, as if trying to explain something. Vaughan shook his head at one point and shrugged at another.

After a prolonged conversation the two parted ways, Morneau joining the line in front of Ambrose.

 'Focused' but not tense

Vaughan says the conversation was "focused," but disagreed that the exchange should be described as tense. And he says he has no disagreement with Morneau. 

"I was just talking about a very particular way [funding] needs to land in Toronto and he was just kind of slowing me down and sort of saying, 'Look, I just launched it,'" Vaughan says

"It's still fairly global, it sort of has to roll through different departments in different ways because, unlike transit, housing is different provinces and different cities and different communities, managed in very different ways. I was just talking about some of the specifics for Toronto. It was a good conversation."

Vaughan added, "All I was talking about was how a specific program needs to be dealt with. And I was just chomping at the bit to get to work at building a program now. … For those of us who have been waiting this long to do the work, we can't get to it fast enough. But that's what you saw. Excitement maybe. But the excitement was positive."

Vaughan said he spent the afternoon with Arnold Chan, the Liberal MP who announced Wednesday he was again dealing with cancer, and that perhaps the strain of that was showing on his face.

In a statement released by his office, Morneau said, "I deeply respect Adam's dedication to the people of Toronto and our community. He is passionately committed to making sure affordable housing is supported in Toronto, as am I. This is an important goal of our government, right across the country.

"We know that this budget provides more help for families than we've seen in over a decade, and we will continue to work together on making an even bigger difference in the lives of Torontonians and all Canadians going forward."

The House is a common meeting place

Beyond serving as a forum for formal debate, the House is a common meeting place where MPs can regularly be seen approaching and talking with each other.

One late night in 2011, for instance, in the midst of an NDP filibuster, Stephen Harper crossed the aisle to sit and chat with Jack Layton, having a conversation the former prime minister recalled fondly months later after Layton died.

Impassioned conversations have also been known to occur in the open. In 2013, Jason Kenney and Jim Flaherty exchanged words after Flaherty objected to comments Kenney made about Rob Ford.

A year earlier, Peter Van Loan crossed the aisle to confront NDP MP Nathan Cullen, which prompted NDP Leader Tom Mulcair to get involved. Video footage showed other MPs intervening to get between Van Loan and Mulcair.

More than a casual chat?

The exchange between Morneau and Vaughan was comparatively tepid, but still seemed more than a casual chat.

Vaughan, who has long advocated for affordable housing, says he is excited about the funding commitment in the federal budget. "I am very passionate about housing," he says.

"I've been working towards where we are right now since I left journalism. And certainly the whole reason I entered federal politics is to get this stuff built. And I can't tell you how thrilled I am to have hundreds and hundreds of millions of dollars tied to the urban infrastructure program for the first time."

The government's affordable-housing agenda remains a work in progress. The budget commits the government to spend $2.3 billion over two years for affordable-housing initiatives, with a further promise to create a national housing strategy "in the coming year."

"I think where there's an opportunity to go a little bit further is in an area like housing, where there's some stopgap measures in this budget and modest increases in investment," Edmonton Mayor Don Iveson told CBC's Power & Politics last week.

"We understand that there's a larger strategy there and we hope that more money will flow in the next couple of years."