The launch of Celebrity Big Brother on Thursday gave Channel 5 one of its largest-ever audiences, with an average of 5.1 million tuning in.
The show and its spin-off programme were the most-watched shows on TV that night between 9pm and 11.30pm, according to overnight data. But the launch figures were slightly down on those for the opening of Celebrity Big Brother on Channel 4 last year.
Last night's debut peaked at six million before 10pm. Contestants include Kerry Katona, Sally Bercow and the Jedward twins. Channel 5 said excluding sport, the launch was the station's most-watched British programme since it went on air.