Celebrities including Olympian Anita Asante and actress Dame Emma Thompson have urged Commonwealth leaders to stand against Britain’s “ill-planned” and “offensive” scheme to send asylum seekers to Rwanda.

More than 20 high-profile names have penned an open letter to attendees of this week’s Commonwealth Heads of Government Meeting (Chogm) in Rwanda, describing the controversial plan as a “scandalous affront” to Africa and the rest of the world.

Many of the signatories have heritage from African Commonwealth countries, including the actress Sophie Okonedo, and actors Martins Imhangbe and Lucian Msamati.

Sophie Okonedo Actress Sophie Okonedo is one of the signatories (Victoria Jones/PA)

They also include the actresses Olivia Colman and Juliet Stevenson, actor David Harewood, television judge Robert Rinder and writers Lemn Sissay and Benjamin Zephaniah.

In the letter, Commonwealth leaders are told they “cannot – must not – stay silent on this offensive scheme”.

It reads: “The message is loud and clear – the prospect of being transported to Rwanda, and African countries like it, is enough to put off even the most desperate people fleeing war and persecution from coming to the UK.

“This tells us much about the British Government’s colonial and insulting view of Africa, as a place that is no better than a dumping ground for things – in this case people – it considers a problem.”

The letter was organised by Together With Refugees, a campaign coalition with a membership of more than 400 national and local organisations.

Asante, one of the signatories, said she is proud to have played football for England and represented Team GB at the 2012 Olympics.

She continued: “But as someone with Ghanian heritage I am disturbed by the UK’s view that sending refugees to Rwanda, or countries like it, is a deterrent to people fleeing war and violence from coming here.

“It’s an insult to Africa. And shames Britain.”