Liz Barker is in her sixth series with Blue Peter

Barker, 30, joined the show in June 2000. She was the first presenter to rejoin the show after becoming a mother following her son's birth in 2004.

"I've absolutely loved my time on the programme but now feels like the right time to say goodbye," she said.

Editor Richard Marson called her a "very special presenter". The programme will continue with four presenters.

Marson said: "She is completely natural and very caring. Audiences love her warmth and she has consistently surprised them - and herself - with her many achievements.

"Blue Peter has never been just a job or a career move for her. We are going to miss her very much and wish her the very best for the future."

Circus high-wire

Barker said she was planning to move her family from London to Cambridgeshire, where she grew up.

"Blue Peter is brilliant but it leaves no room for anything else and there's loads more I'd still love to achieve," she added.

Barker reported for Blue Peter from Vietnam, Morocco, Brazil, Austria, Greece, India and the US, and her adventures have included lawnmower racing, paragliding, walking a circus high-wire, and cleaning windows at London's Canary Wharf tower.