Sally Bercow has reactivated her Twitter account after she closed it when she linked Lord McAlpine to false child abuse allegations.
A former Tory politician was mistakenly implicated by Newsnight's November 2 broadcast in a paedophile ring that targeted children at the care home in Wrexham.
The peer's name was then widely mentioned on the internet, including social networking site Twitter, by users including Mrs Bercow, wife of Commons Speaker John Bercow, comedian Alan Davies and George Monbiot, a columnist for the Guardian.
On November 4, Mrs Bercow posted: "Why is Lord McAlpine trending? *innocent face*."
She deactivated her account, but has now reopened it, writing on the site: "Humbly reactivating account on#Levesoneve *grabs tinsel & mince pies* coz learnt lesson, miss Twitter & will not screw up again. Hello!"
Earlier this month, Lord McAlpine reached a £125,000 settlement with ITV after Phillip Schofield brandished a list of names and handed it to Prime Minister David Cameron during a live interview asking him to investigate them further.
The peer was also awarded £185,000 by the BBC following the botched Newsnight investigation into the alleged child abuse.
Last week, his lawyers confirmed they were still pursuing damages from Twitter users who wrongly tweeted or retweeted the libellous allegations.