Called 'Now You're Talking', the new show will be fronted by just one of the presenters at any one time with Campbell and Sawalha being chosen to front shows that they are seen as best placed to cover. Other presenters may also host the show later in the spring.
'Now You're Talking' will be recorded with a studio audience and aims to tackle a wide range of topical issues affecting the lives and reflecting the views of people across the UK.
A BBC spokesperson confirmed that the corporation is trying out a 30-minute format, as opposed to the one-hour show that Kilroy fronted, to keep things "fresh and punchy" with a tighter focus. Conversely, rival ITV1 chat show 'Trisha' runs for around 90 minutes.
The decision to have only one presenter fronting each show was taken the BBC said because of the "very different styles and backgrounds" of the two presenters.
The BBC is also thinking about using on-screen captions to explain who contributors are when they speak, to have more direct appeal and add context.
Alison Sharman, controller of BBC Daytime, said: "With Nicky's proven track record in hosting lively, topical discussion shows and Nadia's empathy and appeal with the daytime audience, I believe that this will be an exciting and stimulating addition to the BBC daytime schedule."
The first programme will air in early March and is likely to be somewhere in the 9am-10am slot.
Campbell will continue his role as presenter of Five Live's breakfast show and BBC One's 'Watchdog'. He has also worked for Radio 1 and presented 'Top of the Pops'. Sawalha is best known for her role as Annie Palmer in 'EastEnders' and for fronting Granada talkshow 'Loose Women'.
Kilroy-Silk stepped down from the daily discussion show after 17 years, following the publication of anti-Arab comments in The Sunday Express. The spokesperson confirmed that although 'Now You're Talking' will be produced by Kilroy Television, the presenter and former politician will have no editorial input.
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