Cape Town — The foundation which presents Africa's premier prize for good governance has announced a "one-off extraordinary award" of U.S. $1 million to Archbishop Desmond Tutu of South Africa.

The Mo Ibrahim Foundation announced in London on Thursday that it will honour Tutu "in recognition of his lifelong commitment to speaking truth to power".

The announcement comes 10 days before the foundation is scheduled to announce whether or not it will award the Ibrahim Prize for Achievement in African Leadership this year.

That award, made to former heads of state who have left office in the previous three years, has been made only three times since it was launched in 2007.

It is reserved for leaders who were democratically elected, respected term limits and have demonstrated "excellence in office."

The foundation said on Thursday that Tutu's award did not replace the Ibrahim award, but was additional to it. It said this year's Ibrahim award has not yet been adjudicated, but the foundation's experience since 2007 raises the question of whether enough outgoing African presidents meet its criteria to expect it to be granted annually any time soon.

Making the award to Tutu, the foundation said it wanted to recognise "an outstanding African civil society champion."

It added: "Archbishop Desmond Tutu is and has throughout his life been one of Africa's great voices for justice, freedom, democracy and responsible, responsive government.

"In everything he stands for, says, and does, he displays a consistent determination to give a voice to the voiceless and to speak the uncomfortable truth."

Mo Ibrahim, the Sudanese mobile phone pioneer who established the foundation and the awards, said that "whether one always agrees with Archbishop Tutu or not, his contribution to dialogue, to accountability, and to the debate on Africa's future has been unparalleled."

The extraordinary award will be presented to Tutu later this year in Dakar during the annual Ibrahim Discussion Forum, which focuses this year on youth.