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Ontario Premier Doug Ford speaks to journalists during an availability at the Ontario Legislature, on Monday.Chris Young/The Canadian Press

Ontario Premier Doug Ford is considering the creation of an artificial island, requiring millions of tonnes of fill, to house a new multibillion-dollar, two-million-square-foot convention centre off the Lake Ontario shore west of Toronto’s downtown waterfront, according to two sources familiar with the discussions.

A new island, potentially somewhere between the city’s Humber Bay Park and Ontario Place, is one of a handful of locations the Premier and his officials believe has the capacity to house such a massive facility, the two sources told The Globe and Mail.

No extensive feasibility studies or professional analysis has been done on the idea, one of the sources said, and the location is one of several options being explored for a project still in its early stages. The Globe and Mail is not identifying the sources as they were not authorized to discuss the deliberations.

The sources added that extra construction costs and the need to follow federal environmental regulations could complicate an island option. Such a plan would also raise questions about public transit and transportation links.

The province has also considered the Cadillac Fairview-owned East Harbour development site, a former soap factory east of the Don River that is home to a future stop on the provincial government’s Ontario Line subway and where there are large-scale plans for high-density housing and employment space.

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Finding a suitable site in the revitalizing Port Lands area on the city’s eastern shoreline has been discussed, as has making use of the Toronto-owned Exhibition Place, which is also on the future Ontario Line and has large, existing convention facilities that could be expanded.

At recent unrelated public events, Mr. Ford has floated his idea for a new convention centre for Toronto, saying the proposed facility would be “world-class” and cause “shock and awe,” mentioning the large McCormick Place Convention Center in Chicago.

He has not said publicly where his new facility would go, but has suggested a price tag in the billions. He has also in recent weeks mused about the need to find a home for soil excavated from tunnelling transit projects.

The Premier’s Office did not respond to requests for comment.

Braman Thillainathan, a spokesperson for Toronto Mayor Olivia Chow, said Thursday that the city has not seen any formal proposal or received a detailed plan of the Premier’s idea.

“The Mayor has said she is prepared to work with the province on initiatives that strengthen the city and its economy,” Mr. Thillainathan said in an e-mailed statement. “Any major development proposal would be reviewed thoroughly from all angles to ensure it is in the best interest of Toronto and its surrounding communities.”

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Much of Toronto’s downtown shoreline south of Front Street, now covered in tall buildings, was expanded into the lake with fill over the past 175 years.

The bulk of the provincial government’s Ontario Place site – where Mr. Ford is putting an Austrian-owned spa and waterpark and last week unveiled designs for a new $1-billion science centre – is on fill, as is Tommy Thompson Park to the east. As part of a $1.4-billion flood protection plan, the city has created a new island near the mouth of the Don River at its Port Lands site, set for development.

But Fadi Masoud, the director of the Centre for Landscape Research at the University of Toronto, says putting such a large, flat concrete convention centre on new artificial land in the lake could involve hundreds of millions of dollars in extra construction and maintenance costs, trigger environmental hurdles and leave the facility facing flood risks.

“It’s actually insane. I don’t know, I can’t find other adjectives. It’s nuts. It really makes no sense at all,” Prof. Masoud, the author of a book on fill development entitled Terra-Sorta-Firma, said in an interview.

Opposition leaders at Queen’s Park criticized Mr. Ford for focusing on a new multibillion-dollar convention centre instead of shoring up the province’s health-care system or restoring cuts he has made to assistance for postsecondary students.

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“Taxpayers shouldn’t be on the hook for the Premier’s fantasy island,” interim Liberal leader John Fraser said in an interview. “Especially when they can’t get health care or their kids can’t afford college.”

NDP Leader Marit Stiles said the Premier has shown his priorities are at odds with those of everyday Ontarians worried about high grocery prices and long emergency-room waits.

“The Premier likes to spend money on his vanity projects, and it seems to me he’s in some kind of manic frenzy to leave a legacy of megaprojects,” she said in an interview.

Hinting at his plans in the last week, Mr. Ford has said his new convention facility would be a needed major upgrade – more than four times as large – to the existing 442,000-square-foot Metro Toronto Convention Centre (MTCC), which he has complained is too small and has too many escalators.

The Premier has blamed the state of the MTCC, which was last expanded in 1997, for Toronto missing out on convention business that has gone to other cities. The facility, owned by Oxford Properties and operated by a provincial Crown agency, has been consulting with city staff about a proposal to redevelop and dramatically expand, with plans for a hotel and rental housing.

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However, the MTCC site has been the subject of similar pitches for renewal – in a previous iteration, involving a proposed casino – since Oxford bought the site from the federal government’s Canada Lands Co. in 2011.

A 2023 provincial Auditor-General’s report said bookings had sunk significantly and that the centre had a shortage of meeting rooms and “pre-function” areas and needed $17-million in repairs.

If the Toronto-owned Exhibition Place is among the potential candidates for Mr. Ford’s proposed new facility, it’s news to the organization that runs the site, which is home to the annual Canadian National Exhibition summer fair.

Don Boyle, chief executive officer at Exhibition Place, told The Globe this week that his organization had no knowledge of the plans.

The potential for an island convention centre is not the first outside-the-box megaproject the Premier has considered, even as his indebted government is already spending tens of billions on new public-transit lines and more than $2.2-billion alone on his Ontario Place redevelopment.

Mr. Ford has also vowed to construct an up-to-60-kilometre traffic tunnel under the busiest stretch of Highway 401 through Toronto, which some experts have warned could cost $60-billion to $120-billion and would not solve the city’s congestion problems. A two-year feasibility study on the idea is under way.

With a report from Alex Bozikovic