By politics.co.uk staff
Labour is demanding an official investigation into allegations that Michael Gove's special advisers could have broken their code of conduct.
Dominic Cummings and Henry de Zoete faced investigation from the Observer newspaper after the Twitter feed @toryeducation attacked their journalist Toby Helm as an "activist, not a professional hack".
They also stand accused of briefing against ex-Department for Education minister Tim Loughton, after a senior DfE source was quoted on the Spectator website described Loughton as a "lazy incompetent narcissist obsessed only with self-promotion".
Writing to the Cabinet secretary Sir Jeremy Heywood, shadow education secretary Stephen Twigg pointed out the code of conduct for special advisers bans "the preparation or dissemination of inappropriate material or personal attacks".
The code adds: "Any special adviser ever found to be disseminating inappropriate material will automatically be dismissed by their appointing minister."
Twigg's letter forces Gove to either sack Cummings and De Zoete or stand by his special advisers.
He added: "I would also ask you to investigate if official departmental resources have been used, such as official computers, blackberries or phones, to conduct a smear campaign against those who question or criticise the education secretary."
The @toryeducation account has called Financial Times journalist Chris Cook a "stalker" and likened him to Walter Mitty, the Observer noted. The newspaper's editor John Mulholland has also written to Gove demanding an explanation.