UNLIKE its counterparts in Britain and Australia, the state-owned Canadian Broadcasting Corporation (CBC) carries advertising on its television networks, which are sometimes hard to distinguish from their private-sector rivals. But public radio has been ad-free since 1975 and has won a loyal following. A recent independent survey to determine what audiences liked most about the CBC drew 11,000 responses, almost all of which mentioned radio.

But on May 28th when renewing the CBC’s broadcast licence, the Canadian Radio-television and Telecommunications Commission decided to allow two of its four over-the-air radio networks to carry advertising. The CBC says the move is necessary in order to preserve the quality of programming. Not everyone is convinced. Tom Pentefountas, the dissenting vice-chairman of the commission, said the “crazy pursuit” of carrying ads on public radio would destroy the CBC’s brand and erode public support. Ian Morrison, who runs a lobby group representing listeners and viewers, says the decision has put the corporation on the path to further commercialisation.

Like public broadcasters in other countries, the CBC is being asked to do more with less money. When the government announced last year that the CBC’s annual subsidy of about C$1 billion would be C$115m ($113m) lower by 2015, the corporation made plans to cut staff and programming, sell properties and end satellite and short-wave transmission of its international service.

It was already scrambling to raise money. Costumes accumulated since its founding in 1936 are available for hire, as are its mobile studios. Its archives have been mined for books, DVDs and audio recordings. A CBC shop sells everything from mouse pads to lunch bags emblazoned with the corporation’s logo.

Even before the current crisis it was not generously funded. A study of public broadcasters in 18 countries in 2009 found that Canada’s had the third-lowest subsidy (after New Zealand and the United States). The CBC was propped up to the tune of C$34 per person, whereas public broadcasters received the equivalent of C$78 in France, C$111 in Britain and C$164 in Norway, the highest.

The CBC suffered swingeing budget cuts in the 1990s under a Liberal government. But this episode feels more personal. Members of the Reform Party, a forerunner of the ruling Conservative Party, called for the CBC’s privatisation when they were in opposition. The rhetoric softened when the Conservatives came to power in 2006. But the introduction of radio advertising has made listeners wonder if the old Reformers may eventually get their wish. “When the public broadcaster resembles a private broadcaster, the argument that it does not provide an essential service becomes stronger,” Janet Lo of the Public Interest Advocacy Centre told the commission at one of its hearings. Radio ads will help the CBC’s bottom line in the short term, but in time may weaken the case for maintaining its public subsidy.

Correction: An earlier version of this article misstated the size of the cut to the CBC's annual subsidy. The correct figure in the current context is C$115m, not C$45.4m. We regret the error.