LIAM Fox tonight resigned as Defence Secretary over his links with his close friend, lobbyist Adam Werritty.

In a letter to Prime Minister David Cameron, Dr Fox said that he had mistakenly allowed the distinction between his personal interest and government activities to become blurred.

"I have also repeatedly said that the national interest must always come before personal interest. I now have to hold myself to my own standard," he said.

"I have therefore decided, with great sadness, to resign from my post as Secretary of State for Defence - a position which I have been immensely proud and honoured to have held."