Davina McCall's stint as a stand-in host on BBC Radio 2 has attracted more than 150 complaints from listeners.
Davina McCall is best known for hosting Channel 4's Big Brother
The presenter filled in on Ken Bruce's weekday morning show last week.
But the BBC said 156 people complained, while others posted comments about her "inane chatter" and "cringe-worthy" style on the BBC messageboards.
The BBC said it "fully recognised the strength of feeling" but that McCall had extensive broadcasting experience and was a suitable stand-in.
"Davina has a chatty style of presentation and we feel this is in keeping with fellow Radio 2 presenters, such as Chris Evans and Dermot O'Leary," a BBC statement said.
"The Ken Bruce show reaches a broad audience of over six million listeners.
Ken Bruce's show runs from 0930-1200 every weekday
"While we appreciate that Davina's style is different to Ken's, we are also getting a positive reaction from some Radio 2 listeners who are really enjoying the show."
McCall filled in for the first week of Bruce's fortnight-long holiday, while singer Aled Jones will take his place next week.
McCall has been a success as the host of Channel 4's Big Brother since it began in the UK in 2000, but her attempt at hosting a prime-time TV chat show last year was a flop.