Five elderly Kenyans - three men and two women in their 70s and 80s - detained during the 1950s insurgency are the lead claimants in the reparations case to be lodged at the High Court in London on June 23.
The case is being brought by the Mau Mau War Veterans' Association and the Kenya Human Rights Commission, through a London law firm. Earlier suits in 2006 and 2007 were denied.
If the five claimants are successful, thousands of other people imprisoned and abused during the 1950s and early 1960s could be added to a potentially huge class action suit.
An estimated 90,000 Kenyans were executed and 160,000 people detained during the insurgency including Onyango Obama, grandfather of President Barack Obama.
Gitu Wa Kahengeri, 79, spokesman for the Mau Mau War Veterans Association, who spent seven years in detention camps, said that the advanced age of the veterans meant the claim was extremely urgent. "Britain knows what it did. It would be morally wrong to deny us."
The UK government has said the claim is invalid because of the time lapsed since the alleged abuses. But Kenyan lawyers respond that it has taken long to secure justice because the so-called “Mau Mau” movement had been illegal in Kenya for 51 years. President Kibaki lifted the ban in 2003.
The Kenya Human Rights Commission has said 90,000 Kenyans were executed, tortured or maimed during the crackdown, and 160,000 were detained in appalling conditions.