OTTAWA -- The chairman of the board of Bombardier, a scion of the Rotman family, the chairman of a major power company -- these prominent Canadians all gave as much money as they're allowed, or close to it, to both the Liberals and Conservatives in 2018.

They are among at least 20 Canadians who gave substantially to the country's two most fiercely opposed parties last year, according to an analysis of public Elections Canada documents by The Canadian Press. Such donations are fully legal: a person can give to all the political parties if he or she wishes. But they are unusual.

Annual returns for last year submitted by the two parties were compared by both names and postal codes to find people who gave 90 per cent or more of the maximum donation, which at the time was $1,575. Names listed on the returns of both parties that were paired with different postal codes were excluded.

The resulting list is a who's-who of the upper crust in Canada, including numerous corporate executives, officers of the Order of Canada, and people with buildings named after them.

There are Blake Goldring and Amy Kaiser -- the former an officer of the Order of Canada and executive chairman of AGF Management Ltd., the latter a former chair of the SickKids hospital foundation and a professor at the University of Toronto.

There are also David Cornhill, the former chair of AltaGas; Gordon Rawlinson, who owns Rawlco Radio based in Saskatchewan (his wife is also on the list); and Donald K. Johnson, the investor who is also a member of the Order of Canada.

Add those to the aforementioned Pierre Beaudoin (Bombardier), Kenneth Rotman (Clairvest Group), James Temerty (Northland Power), and several others.

Multiple people on the list made their donations to each party on the same day.

The Canadian Press attempted to reach many of the donors, but most did not respond or declined to comment.

The one donor to respond, the former chair of the Canadian Jewish Political Affairs Committee Sherry Firestone, said her donation to the Liberals was for a fundraiser and the donation to the Conservatives was a fee for attending the party's 2018 convention as an observer.

In an emailed statement, a spokesperson for the Liberals highlighted the "growing success" of their grassroots fundraising and emphasized the implementation of transparency rules around the party's fundraising events.

A spokesperson for the Conservative party said if someone "chooses to donate to multiple parties, they're within the rules to do just that." He said due to the volume of donations the party receives, the number of dual-party donors was not particularly notable.

People who max out their individual donations to both parties are "hedging their bets" ahead of the fall election, according to Duff Conacher, the head of Democracy Watch, an ethics watchdog.

"With those donations, they are able to at least buy access to the top people in the parties, and having that access gives them a chance to have influence over their decisions," Conacher said.

Conacher also said that, given the maximum donation is so low relative to the sums that used to be spent for corporate donations that are no longer permitted, it made sense for those looking for access to max out their contributions to both parties.

After the Liberal government was elected in 2015, it made a pledge that "there should be no preferential access to government, or appearance of preferential access, accorded to individuals or organizations because they have made financial contributions to politicians and political parties."

But the party soon faced criticism for a series of fundraisers that were attended by people lobbying the government.

The Liberals responded by publishing lists of attendees at fundraisers, though they were accused of not living up to their own rules as late as September 2018.

The Liberals have also on occasion accused the Conservatives of holding cash-for-access events, and of a lack of transparency.

At the beginning of this year, new rules from Elections Canada came into force obliging parties to disclose fundraising events to Elections Canada.