Sally Bercow, the wife of the Commons Speaker, is being sued for libel over a tweet that allegedly linked a former Conservative politician to false child abuse allegations.
Law firm Carter-Ruck has confirmed it is representing Mrs Bercow, a former Celebrity Big Brother contestant and Labour council candidate against a £50,000 claim by Lord McAlpine.
The peer was mistakenly implicated in a paedophile ring that targeted children at a care home in Wrexham by the BBC’s Newsnight on 2 November.
Lord McAlpine’s name was then widely mentioned on the internet, including social networking site Twitter, by users including Mrs Bercow, comedian Alan Davies and Guardian columnist George Monbiot.
A spokesman for Carter-Ruck confirmed the firm was representing Mrs Bercow, 43, against Lord McAlpine. “He’s limited his claim to £50,000 in the court,” the spokesman said.