The BBC could face a battle to hold on to its most popular show, The Great British Bake Off, as the current three-year deal for the show runs after next year’s seventh series.

Last week’s final of the BBC1 show, won by Nadiya Hussain, was the most watched TV show of 2015 to date with a peak audience of 14.5 million viewers.

But despite the success of the show, which has a bigger audience than BBC1’s Saturday night hits such as Strictly Come Dancing, Giedroyc and Perkins are not believed to be among the BBC’s highest earners.

Negotiations around a new deal, expected to start imminently, come at a time when the BBC’s finances are under pressure as it negotiates its future size and funding with the government, and the amount it pays its top stars is under close scrutiny.

Any move away from the BBC would allow for greater commercial opportunities, such as product placement, but would have to be balanced against the dip in audience in its new home away from BBC1, the most-watched channel in the UK.

One of the BBC’s biggest hits, the first final of the show was watched by 2.5 million viewers in 2009.

It grew by around 2 million viewers ever year to 8.4 million by 2013, when it was won by Frances Quinn, before leaping another 50% to 12.3 million last year, its first after it switched form BBC2 to BBC1.

This year’s final saw a further increase of more than a million viewers to an average of 13.4 million and a five-minute peak of 14.5 million.