The group competing against the Ottawa Senators for the right to redevelop LeBreton Flats is backed by a pair of Quebec-based billionaires, and plans to build an underground, NHL-style arena, CBC News has learned.

DCDLS, led by Devcore Group, is competing against Rendez Vous LeBreton Group, led by Ottawa Senators owner Eugene Melnyk, for the right to redevelop the 9.3 hectares of land just west of downtown Ottawa — with the option of taking on an additional 12.3 hectares.

The two groups are bidding for the two parcels in red at LeBreton Flats, just west of downtown Ottawa, while the two parcels in yellow could also be redeveloped by the winning bid. (National Capital Commision) DCDLS includes billionaire André Desmarais , the son of the late Paul Desmarais , once the richest man in Quebec, whose estate was worth about $5.6 billion US in 2015. CBC News has learnedincludes billionaire, the son of the late Paul, once the richest man in Quebec, whose estate was worth about $5.6 billion US in 2015.

Major players in the bidding process say Guy Laliberté, founder of Cirque du Soleil, also backs the DCDLS bid.

According to Forbes, Laliberté was worth $2.1 billion US in 2015, and recently sold most of his shares in Cirque du Soleil.

Devcore Group also features Montreal-based developers Broccolini and Canderel, construction firm Pomerleau, plus three architects — Richard Brisbin, Claude Provencher and Moriyama & Teshima.

Both bids include a sports and entertainment centre and a new main public library, while sources familiar with the DCDLS bid told CBC News that plan recently included the following:

Central library/National Archives building up to 200,000 square feet.

NHL-style arena almost entirely underground (two storeys above ground).

Automotive museum.

'Brewseum' beer museum sponsored by Molson Coors Brewing Company.

YMCA.

Farm Boy.

Skydiving simulator.

Botanical garden/man-made beach.

LeBreton Flats plans revealed Tuesday

DCDLS plans to meet with Ottawa Mayor Jim Watson on Monday, just one day before presentations to the National Capital Commission, CBC News has also learned.

Ottawa Senators owner Eugene Melnyk has previously said he would not consider having his team play at an arena he doesn't control. (CBC) DCDLS . The two competing groups will present their bids to the NCC board of directors before public consultations on Tuesday and Wednesday at the Canadian War Museum — a building coincidentally designed by one of the architects involved with

Rendez Vous Lebreton Group also reportedly includes Windmill Developments, which is building the Zibi Development on the shores of the Ottawa River.

Rules stipulate neither group can reveal details of their plans to the public or any third party before the presentation to the NCC on Tuesday.

The NCC is expected to announce the successful bid in early 2017.

Below are recent projects built by members of the DCDLS bid.