David Cameron is in Liberia for talks on international development targets and will have a "historic opportunity" to lift 350 million children out of extreme poverty, charities said.
On the third leg of his tour of Africa, the Prime Minister will co-chair a United Nations meeting on what happens after the Millennium Development Goals (MDGs) expire in 2015.
More top news
TV presenter Helen Skelton is a supporter of the campaign and is calling for more parents to get out on their bikes with their children.
Mrs Justice Nicola Davies will sentence Berlinah Wallace, 48, at Bristol Crown Court.
The JR4NHS group was founded by three doctors and a university professor, and supported by the renowned physicist until his death in March.