Damian McBride, the prime minister's former press adviser, has resigned following controversy over e-mails which reportedly discussed smear stories about Tory MPs.
Here is Mr McBride's resignation statement in full:
I am shocked and appalled that, however they were obtained, these e-mails have been put into the public domain by Paul Staines.
When Derek Draper originally suggested using a website to compete with the kind of material seen regularly on the Guido Fawkes blog, he asked me in a personal capacity to write up some of the stories doing the rounds in Westminster.
Derek and I decided in the end that this website was the wrong thing to do, and that Derek should not take his online efforts down to the level of Guido Fawkes and his Tory backers.
I have already apologised for the inappropriate and juvenile content of my e-mails, and the offence they have caused, but I did not want these stories in the public domain - it is because Paul Staines has put them there, and I am sickened that he has done so.
However, we all know that when a backroom adviser becomes the story, their position becomes untenable, so I have willingly offered my resignation.
It has been an absolute privilege to work for Gordon Brown and the Labour government in the Treasury and in Downing Street, they will always have my full support, and I regret any embarrassment I have caused them.