NDP Leader Jagmeet Singh has made it clear he is comfortable not running for a seat in the House of Commons before the 2019 federal election. But he has opened the door to running in a byelection in a riding in which he has a "genuine connection" and which "makes sense."

Singh has laid out the criteria. So where could he run in 2018 if the opportunity presents itself — and where could he win?

In an interview with CBC Radio's The House, Singh told host Chris Hall, "I'm comfortable where I am right now and I'm open, though, to an opportunity that arises that I have a genuine connection to that makes sense."

Asked to define what that means, Singh identified three parts of the country, all in southern Ontario.

"An area that I have some history with, an area that I can connect with constituents," he said. "I've represented Brampton, Mississauga for a number of years. Downtown Toronto is an area that I have a strong connection to. Windsor, also, I have a strong connection, having lived in Windsor for a number of years."

In each of these regions, there are seats that are potentially winnable for Singh and the NDP. But there are also a few obstacles that might force him to wait.

With NDP support stagnant and the party posting losses in all six of the byelections that have occurred during Singh's short tenure, whether he can afford to wait is an open question.

Connection to Brampton

Singh was first elected for the Ontario NDP in the riding of Bramalea–Gore–Malton, a riding straddling parts of both Brampton and Mississauga, in the 2011 provincial election. The bulk of that riding is contained within the federal boundaries of Brampton East, the seat that Singh has identified as the one he will most likely contest in 2019.

Defeating incumbent Liberal MP Raj Grewal will not be easy. Grewal won by a margin of more than 29 percentage points over both the Conservative and NDP candidates.

But Singh has shown he can beat daunting odds. The New Democrats had just 12 per cent support in the 2007 provincial election in Bramalea–Gore–Malton. Singh boosted that score to 38 per cent four years later and 44 per cent in 2014.

NDP leader Jagmeet Singh talks about what he needs to do to establish himself as the main alternative to Justin Trudeau ahead of the next federal election 13:23

This suggests that a low score for the NDP in a previous election might not be an insurmountable obstacle for Singh in Brampton. But Brampton East might be his best hope for a victory. In addition to his history in the riding, it was the one with the highest NDP support in Brampton in 2015 and the only one in which the NDP was even somewhat competitive.

The question is, however, whether he might get the opportunity to demonstrate his local connections in a byelection in 2018. The Liberals hold all five Brampton seats and all six seats in Mississauga (where the NDP's chances look even slimmer, as they lost all six by 39 points or more in 2015).

The five Brampton Liberal MPs are all in their first term. Barring health issues, scandal or tragedy, none of their seats are likely to become available before the next federal election.

Options, but few opportunities

While Singh might not have the same ties to downtown Toronto as Brampton, his party has stronger roots there.

The NDP won eight seats in Toronto in 2011 before being swept out of the city in 2015. But they did finish second in nine ridings, including three in which the margin was less than three points (Davenport, Parkdale–High Park and Toronto–Danforth). If any of these became available, it would meet Singh's criteria of "making sense" — i.e., being winnable.

A number of ridings in the city have a history of voting for the New Democrats and will be battlegrounds in 2019 as the Liberals attempt to maintain their monopoly on the city.

But that means these seats run into the same problem as those in Brampton. They are filled by first-term Liberal MPs, including a few parliamentary secretaries and the ministers for immigration, refugees and citizenship, foreign affairs and finance. They are unlikely to oblige the NDP leader with a vacancy.

Windsor makes sense but it's taken

So if Liberals in Brampton, Mississauga and Toronto won't be making way for Singh, that leaves the last city to which the NDP leader says he has a genuine connection: Windsor.

A hub of the automotive industry, Windsor has long been an NDP stronghold and is where Singh grew up. It was one of the few regions of the country in which the NDP gained seats in the last election, sweeping both urban ridings as well as the neighbouring and more rural Essex seat.

But that these three ridings are held by the NDP would seem to rule them out as byelection options for Singh.

"I'm not going to be asking anyone to step down and to disrupt their connection with their community," Singh told The House.

Such a demand would be especially hard to make of the Windsor area's two first-term NDP MPs, Cheryl Hardcastle in Windsor–Tecumseh and Tracey Ramsey in Essex.

Singh, second from left, with Windsor-area MPs Cheryl Hardcastle, second from right, and Brian Masse, right. (Chris Ensign/Twitter)

Brian Masse, however, has held Windsor West for almost 16 years, having won the seat in a 2002 byelection. With a margin of 26 points and more than 12,000 votes over the Liberal candidate in 2015, Masse's seat is one of the three safest NDP ridings in the country.

Singh's Brampton connection can make him a winner there and the NDP is still competitive in Toronto, but in neither city are seats likely to become available. Windsor is both friendly territory for the NDP and has a connection to Singh, but he won't ask his incumbents to step aside.

The next election is just 21 months away — a blip in a veteran parliamentarian's political career. But they might be decisive ones in Singh's leadership of the NDP. Unless someone voluntarily makes room for him, he will likely spend the next 21 months outside the House of Commons, whether he is comfortable with that or not.