Lord McAlpine will face Sally Bercow, wife of the House of Commons speaker, in the high court after she refused to apologise for a tweet linking McAlpine to allegations of child abuse.
According to the Guardian, McAlpine filed a formal libel claim on 7 December after trying to settle with Bercow out of court.
On 4 November, Bercow tweeted: "Why is Lord McAlpine trending? *innocent face*"
She later tweeted "Final on McAlpine: am VERY sorry for inadvertently fanning flames. But I tweet as me, forgetting that to some of u I am Mrs bloody Speaker." before deleting her account.
In November it was revealed that the lawyer for the ex-Tory party treasurer was to pursue ‘at least 20’ high profile tweeters.