Denis Leary was the first guest on the show

A statement from Rise said: "It had become obvious for some time that Mark's interpretation of the show was at odds with the rest of the production team. We wish him luck in the future."

It added that Ms Turness had 13 years' experience at ITN and she would be a "valuable" member of the team.

Rise is fronted by a team of seven young presenters who deliver a mixture of serious and irreverent news.

Sky Sports rugby presenter Mark Durden-Smith anchors the show, which is broadcast from a high-tech studio with a breakfast bar instead of sofas.

'Wooden'

Rise replaced The Big Breakfast, which had ratings of 300,000 when it ended, well down from its peak of more than one million when Chris Evans and Gaby Roslin hosted the show 10 years ago.

Viewing figures for Rise have placed it last among the terrestrial channels, even behind children's shows on BBC Two and Channel 5.

BBC News Online received hundreds of e-mails from its readers after the show was broadcast, most of which were negative about it.

"Wooden presenters, bad content presentation and extremely dull," was how viewer, called Nick, described it.

But others said it had potential, and praised attempts to be different, such as the lack of theme tune.

"Hopefully, this will develop into a much classier version of the Big Breakfast, and entertain as well as educate," wrote another reader called Matt, from Coventry.