David Cameron has hailed the anti-corruption summit he is hosting in London as "the biggest demonstration of the political will to address corruption that we have seen for many, many years".
The summit has brought together more than 40 countries including 12 heads of state and government.
Speaking at the end of the first day, he said attendees had shown "far more political will not just for words, but for action that will make a difference".
David Cameron "has egg on his face" after being filmed telling the Queen there are some "fantastically corrupt" countries coming to a UK anti-corruption summit, Labour said.
The party likened the episode to another gaffe - when Mr Cameron was caught revealing how the Queen "purred" with pleasure when he told her Scots had rejected independence.
"This is another gaffe from the PM - you'd hope he'd have learned his lesson when it comes to off the record comments and the Queen but sadly not," Wes Streeting MP said.
"The fact that David Cameron has egg on his face shouldn't deflect from the more serious issue: for all his talk about corruption he's failing to act.
"If the PM really is serious about tackling corruption at the summit this week he needs to get his own house in order and make good on his promise to deliver public registers of beneficial ownership for the UK crown dependencies and overseas territories."
David Cameron hoped to sign up a global declaration against corruption - but only six countries put pen to paper.
Why is it happening? Who is going? And will it get awkward after the Prime Minister's 'corruption gaffe'?
David Cameron has praised Nigeria and Afghanistan for the action they have taken in combating corruption.