Education secretary Michael Gove could be facing an investigation over allegations that his advisers sent abuse to journalists on Twitter.
The row, which was investigated by the Observer, was sparked after an anonymous twitter account @toryeducation attacked the paper's political editor Toby Helm.
Michael Gove has come under fire for the alleged conduct of two of his special advisers
Labour's Shadow Education Secretary, Stephen Twigg has written to Cabinet Secretary Jeremy Heywood requesting an investigation be launched into the conduct of two of Gove's Special Advisers following the smear allegations contained in the Observer.
The account also apparently attacked the Financial Times' education correspondent, Chris Cook, suggesting he is a "stalker" and accused Helm of being "a Labour stooge" and promoting Britain's entry to the Euro while he worked at the Daily Telegraph, calling him "an activist, not a professional hack".
The Observer alleged that two of Gove's special advisers Dominic Cummings and Henry de Zoete contibuted to the Twitter feed, and had been asked to tone down the feed's output in 2011 by Henry Macrory, then Tory party head of press.
Both advisers, whose salaries are paid by the taxpayer, have denied contributing to the feed.
After Twitter speculation about the Observer story, Ladbrokes reported a rush of money on Gove to be next Cabinet exit, slashing odds from 25/1 to 8/1.
After the story's publication, the Twitter account @toryeducation, retweeted an attack on the Observer's Helm, written a year ago by fellow journalist Sarah Vine, Gove's wife.
Ministers are held responsible for the conduct of their advisers, under new rules devised following the Labour party scandal where a spin doctor, Damian McBride was found to be planning to spread flase rumours about high-profile Tories.
According to the code, advisers "should avoid anything which might reasonably lead to the criticism that people paid from public funds are being used for party political purposes… the preparation or dissemination of inappropriate material or personal attacks has no part to play in the job of being a special adviser as it has no part to play in the conduct of public life.
"Any special adviser ever found to be disseminating inappropriate material will automatically be dismissed by their appointing minister."