The Guardian has reported that Adams, a former Lansons PA head and private secretary to Tony Blair, has been sued for a ‘persistent and public campaign’ against Cruddas on social media.
Adams quit his job as Lansons acting head of PA in December 2011 to launch a pro-lobbying campaign and the Standup4lobbying blog.
The legal action came after accusations repeatedly aired by Adams online that Cruddas had breached the Political Parties, Elections and Referendums Act 2000.
These allegations follow a story by the Sunday Times, which Cruddas is also understood to be suing, using undercover footage and published in March 2012.
Both police and the Electoral Commission said that there was no evidence that Cruddas, who resigned following the story, had broken the law in soliciting donations.
The Guardian reported that in a hearing today Justice Eady said Adams' claims were false and ordered him to pay £45,000.
Additionally, he must pay a further £40,000 of Cruddas’ estimated £120,000 legal costs within three months, with a further amount to be agreed.
The Guardian reported that Justice Eady told the court: ‘A significant number of readers who were interested in following the subject, at least those who are fair minded, will have come to recognise some months ago that Mr Adams's charges were actually just silly and not, after all, to be taken seriously.’
Adams did not respond to a request for comment.