Labour is pushing for Jeremy Corbyn to face Theresa May in an hour-long head-to-head Brexit debate on ITV on Sunday 9 December, in a primetime slot before the finale of I’m a Celebrity, Get Me Out of Here.

Since Corbyn accepted May’s challenge to engage in a debate over the prime minister’s Brexit deal, broadcasters have been in discussions with Downing Street and Labour, with ITV, the BBC and Sky vying to host the confrontation.

Labour strongly favours the proposal presented by ITV, which would see the two leaders debate with each other directly in a slot previously earmarked for an I’m a Celebrity-themed edition of the quiz show Catchphrase.

A Downing Street source confirmed they had also met the broadcasters on Tuesday, but did not express any preference.

If ITV wins out, the show would air just two days before MPs must vote on the Brexit deal in the House of Commons, in what May has described as “one of the most significant votes that parliament has held for many years”.

A Labour source said: “ITV’s proposal promises the largest and most demographically-diverse audience with a prominent peak slot 48 hours before the meaningful vote.”

The BBC would plan to air its programme on the Thursday before the vote, rather than disrupt its Sunday night schedule, which features the Strictly Come Dancing results show and Doctor Who.

The BBC was also offering a more complex format, with other participants involved aside from the prime minister and the Labour leader, sources said.

“A pure head-to-head debate, as ITV propose, would be the best and most in-depth format for the viewing audience, providing real scrutiny and avoiding complex and unpopular multi-headed formats,” the Labour source said.

The prospect of Corbyn and May – both of whom would press ahead with Brexit – appearing alone has sparked a row, with hard Brexiters including the former foreign secretary Boris Johnson, and supporters of a second referendum, including the Green party’s Caroline Lucas, keen to be involved. The Scottish first minister, Nicola Sturgeon, has also staked a claim.

The idea of a debate on the deal, which was formally endorsed by EU leaders in Brussels last weekend, emerged from No 10 this week, as May’s team struggle to get their arguments heard over a barrage of criticism in Westminster.

They believe the prime minister would perform well, because she has been immersed in the detail of the 585-page withdrawal agreement containing the backstop proposal for Northern Ireland and the much shorter political declaration about Britain’s future relationship with the EU.

The BBC has already begun its own preliminary work on potential general election night coverage, checking the availability of a studio for either a new vote or a second referendum.