The search to find Britain’s best young speaker reaches its grand finale tonight. Together, the three finalists have seen off thousands of other contenders. They’ve undertaken months of challenges and speeches with expert guidance from their mentors, Kate Silverton, Deborah Meaden, Alastair Campbell and Earl Spencer, and faced the scrutiny of the series’ judges, Jo Brand, John Amaechi and Jeremy Stockwell. In last night’s semi-final they addressed the nation to win their place in final. Now, they face a life-changing trip to Malawi with Unicef to research and prepare their speeches for the final showdown.

Following some words of advice from Unicef Ambassador Ewan McGregor, the final three travel to Malawi’s capital, Lilongwe, and each of them is assigned a different aspect of children’s rights for their speech – the right to water, the right to education and the right to survive. They have five days to investigate and research their topics.

During the course of their visit they meet children whose lives have been changed by a school built in brick, rather than just under the trees; a 13-year-old girl living with HIV; and discover the difference a proper well can make to village life.

Once back in London, they have a few days to collect their thoughts and prepare their speeches, before they journey to St John’s Smith Square to make the speech of a lifetime. The four mentors are all back for the final episode to sit on the judging panel alongside Jo, Jeremy and John – a truly daunting prospect. But who will be crowned Britain’s Best Young Speaker 2009?

Wednesday 29 April
8.00-9.00pm BBC TWO