The Conservative Party in Britain has demanded a personal apology from Prime Minister Gordon Brown over defamatory emails circulated by a government aide.
The aide, Damien McBride, resigned after details of the emails emerged, including unfounded and obscene claims about the private lives of leading opposition politicians.
The Conservatives are accusing Mr Brown's team of engaging in gutter politics.
Cabinet Office minister Liam Byrne has said the prime minister knew nothing of the emails. A Labour backbencher has called for an inquiry to find out who was involved.
The incident is embarrassing for the government, following a scandal over interior minister Jacqui Smith, whose husband "mistakenly" submitted an expense claim for pornographic films he had viewed.