LONDON - BRITISH Prime Minister Gordon Brown faces awkward questions when he returns from his Easter break after his special advisor quit after sending 'obscene' emails about opposition politicians.

Damian McBride, one of Mr Brown's closest aides, resigned after reportedly trying to 'smear' the leader of the main opposition Conservatives, David Cameron, and other senior Tories in emails sent to a former spin doctor.

The prime minister said there was 'no place' in politics for such material and sources in his Labour party confirmed McBride would not receive a pay-off.

The government has insisted that the emails were solely the work of Mr McBride, who was Mr Brown's political spokesman until last year when he was shifted to become head of strategic planning in the prime minister's office.

But furious Conservatives accused Mr Brown of creating a 'corrupting culture of spin' - and Labour figures also made clear their distaste at the activities of Mr McBride.

The Conservatives' foreign affairs spokesman William Hague called for Mr Brown to make a full apology. 'This has happened at the heart of his government right inside Downing Street,' Mr Hague said.

'It is very important that he shows personally that he takes this very seriously and that it is not going to happen again.' Some commentators suggested the leaked emails had exposed a clumsy attempt to mount a dirty tricks campaign ahead of a general election which must take place by the middle of next year.

Despite receiving a minor rise in support for his handling of this month's G20 summit on the world economy in London, Mr Brown and Labour remain firmly behind the Conservatives in opinion polls.

The episode - which inevitably quickly acquired the label 'smeargate' in media reports - also highlights the growing role of blogs in British political life. Mr McBride reportedly intended the allegations about the personal life of Mr Cameron and the Conservatives' finance spokesman George Osborne to be published on a new political blog with the preliminary title 'Red Rag' whose purpose would be to attack the Conservatives.

Mr McBride sent the emails to Derek Draper, a one-time Labour spin doctor who runs the LabourList website for Labour supporters.

But they were leaked by Paul Staines, the author of a popular right-leaning blog that trades in political gossip and rumours called Guido Fawkes which takes its name from one of the leaders of a plot to blow up parliament in 1605.

Staines claimed the material was 'obscene' and said it was 'evidence of a long-term smear operation run out of Downing Street.' On his website, next to a picture of the disgraced Mr McBride, Mr Staines wrote: 'Mission accomplished.' Gaby Hinsliff, the political editor of the Observer newspaper noted Sunday: 'Yesterday marked the British blogosphere's first big political scalp, and the day political new media in the UK came of age.' Labour figures joined their Conservative foes in condemning the smear attempts. -- AFP