“Nigeria n Afghanistan most corrupt countries in the world" – UK Prime Minister Cameron

Mr Cameron was caught on microphone ahead of an anti-corruption summit describing Nigeria and Afghanistan as "possibly two of the most corrupt countries in the world" to the Queen. 

The PM was seemingly unaware his conversation with the Queen - in front of the Archbishop of Canterbury and the House of Commons Speaker John Bercow - was being recorded.

He said: "We had a very successful Cabinet meeting this morning, talking about our anti-corruption summit.

"We have got the Nigerians - actually we have got some leaders of some fantastically corrupt countries coming to Britain.

"Nigeria and Afghanistan - possibly two of the most corrupt countries in the world."

In the wake of the gaffe, Mr Cameron has been accused of failing to recognise "important progress" made by the two countries in their efforts against corruption.

Garba Shehu, a spokesman for Nigerian President Buhari, said: "This is embarrassing to us, to say the least, given the good work that the President is doing.

"The eyes of the world are on what is happening here. The Prime Minister must be looking at an old snapshot of Nigeria."

The Afghan embassy also questioned the accuracy of Mr Cameron's description, telling Sky News: "President Ghani and his government since in office have taken major steps to fight corruption.

"Countering corruption is a top priority along security issues for the National Unity Government. Therefore calling Afghanistan in that way ... is unfair."  A Downing Street statement said that both leaders have acknowledged the scale of the corruption they face in their countries.

A spokesman said: "In a collection of essays on the fight against corruption to be published on the day of the Summit, President Ghani writes that Afghanistan is 'one of the most corrupt countries on earth' while President Buhari writes that that corruption became a 'way of life' in his country under 'supposedly accountable democratic governments'."

"Both leaders have been invited to the Summit because they are driving the fight against corruption in their countries. The UK stands shoulder to shoulder with them as they do so."