Six British politicians have written to the Rwandan President, Paul Kagame, calling for two former military officers to be released from prison.
Frank Rusagara - who was once defence attaché to the UK - and Tom Byabagamba, were arrested five years ago.
They were charged with spreading rumors and tarnishing the image of Rwanda and its government.
A military court sentenced them to 20 and 21 years in prison respectively.
The politicians, from Britain's upper and lower houses of parliament, described the sentences as disproportionate.
They said they were concerned about the health of the detainees and asked President Kagame to release them on compassionate grounds.