The expansion of the bid will include the cantons of Valais, Bern, Freiburg and Obwalden, along with original bidding city Sion.

They will all work the with the Federal Government and the Swiss Olympic and Paralympic Committees during the bidding process.

The decision has led to the creation of a new body for the candidature of the Games entitled "Organisation for the Swiss Olympic Candidature", which will be led by Thomas Gurtner and will develop the bid in the coming months, focussing on the building programme and legacy of the Games.

It could mean events being shared around existing infrastructure as a cost-saving measure.

Jürg Stahl, who is leading the bid for the 2026 Games, expressed his delight at the inclusion of the extra cantons.

"In the weeks leading up to the turn of the year, many have pledged their support and the candidacy is now a real Swiss candidacy," he said.

"We need this solid foundation.

"We will succeed if the Games are local, regional, cantonal and, finally, nationally anchored."

Frédéric Favre, vice-president of the Sion 2026 bid and a councillor in the canton of Valais, added: "The Games will make Switzerland and the Valais region known around the world.

"For our region, which depends heavily on tourism throughout the year, this is an extraordinary trump card."

International Olympic Committee (IOC) President Thomas Bach said this week that he is reluctant to predict the outcome of a local referendum which could ultimately decide whether Sion submits a bid for the 2026 Games.

There are fears that Sion's bid could be overruled by locals as they have concerns about the costs of hosting the event, despite the approval of a series of money-saving measures for Games hosts announced by the IOC on February 6.

"This is very difficult to tell," Bach said at this week's IOC session held before Pyeongchang 2018.

"The candidate of Sion has already taken many options which the agenda is offering into consideration and they already benefit greatly from these reforms.

"But these referenda in western countries are not only decided on the numbers.

"What you can see in a number of western countries is that big projects which are orientated to the future have difficulties in winning referenda - be it a new airport, a new motorway or, in my country, train station, or many others."

Bach then added that citizens tend to "expect a return on investment tomorrow and not necessarily in seven or 10 years".

Calgary in Canada, Stockholm in Sweden, Sapporo in Japan and either Reno, Denver or Salt Lake City in the United States are other contenders for the 2026 Games.

Numerous bids for the Summer and Winter Games have collapsed in a referendum in recent years, including Austrian city Innsbruck in the 2026 race.

The deadline for bidding cities to enter the candidature process for the 2026 Games is March 31.