In a statement, the group said details of the full "cost over-run coverage and cost sharing with other levels of Government" have not been made available far enough in advance of a vote on the issue next month.

A plebiscite on whether Calgary should or should not host the Games is scheduled for November 13 and the City Council have organised 17 public engagement events beforehand.

These are to ensure locals "have multiple mediums and opportunities to engage", it is claimed.

Calgary 2026 chief executive Mary Moran has said she felt they have shared "more information than most jurisdictions have in the past".

However, NoCalgaryOlympics say a lack of a partner funding agreements and the clarity of cost over-runs "should stop the bid".

Last month, the Calgary 2026 Bid Committee released their proposals for the Games, in which they said hosting would cost CAD$5.3 billion (£3.1 billion/$4 billion/€3.5 billion), which includes CAD$3 billion (£1.8 billion/$2.3 billion/€2 billion) of city, provincial and federal funding.

However, a City Council document was then leaked which suggested the figure could in fact be higher, because of potential costs associated with building an Athletes' Village in Victoria Park.

NoCalgaryOlympics now claim a deadline for full cost details to be made available 30 days prior to advance polls on the issue has passed.

"Our position is that with risks and costs not fully known, citizens need to say no," said the group's founder Daniel Gauld.

"In fact, we wonder why City Councillors haven't already taken an off-ramp as they've watched commitment after commitment, deadline after deadline, not met."

The organisation's statement added: "NoCalgaryOlympics questions whether Calgary will have full, quality, relevant information so that people will understand what they are voting on."

It is widely expected that if the city votes against hosting the Games in the plebiscite then the bid will collapse, but the result will not be binding, meaning it is possible they could press on regardless.

As part of their statement the group say they have asked the City Council to confirm whether "the voice of citizens reflected in the plebiscite" will be the most important factor influencing their decision to continue.

Yesterday the Calgary bid, along with two others from Italy and Sweden, were officially approved by the International Olympic Committee (IOC) as candidates for the 2026 Games.

Both the Swedish capital Stockholm and the joint Italian bid involving Milan and Cortina d’Ampezzo are also facing serious issues which could see them derailed, however.

Stockholm's bid lacks political support from both the Swedish Government and their City Council, while the Italian Government have already said they will not provide financial support for the Milan-Cortina d'Ampezzo bid.

If they survive long enough, each of the Bid Committees will have to submit formal candidature files to the IOC by January 11, 2019.