Anti-Israel politician George Galloway is taking legal action against Twitter users who he claims have libelled him, it has emerged.
He is demanding thousands of pounds from people who posted tweets alleging that he was antisemitic.
The Bradford West MP has instructed Chambers law firm in the city to send pre-action letters, which demand recipients each pay damages and legal costs amounting to more than £5,000.
The letters were sent last week and followed Mr Galloway's appearance on the BBC's Question Time programme filmed in Finchley, north-west London, last month.
During the show he was asked to comment on the rise of antisemitism in Britain.
MP is demanding damages and costs of £5,000
Ron McKay, Mr Galloway's spokesman, told the Guardian that the number of letters ran "into double figures". He said that the money demanded was for legal costs.
One of the recipients of a letter said she had not slept since receiving it. "It was intimidatory," she said.
Jewish journalist Hadley Freeman is also being sued by the Respect Party MP for a tweet she posted on the social-media site following the broadcast. Lawyers for the Guardian, the newspaper she works for, are now advising the columnist.
Jewish barrister Jeremy Brier has offered free advice to those being sued. The JC understands a team of lawyers is working to put together a co-ordinated response to the letters.
One of them, Mark Lewis, said he would report Mr Galloway's lawyers to the Solicitors Regulatory Authority (SRA) and the West Yorkshire Police about the demand for costs.
An anonymous Twitter account has also been set up providing legal advice to those facing action from Mr Galloway.
A spokesman for the SRA said the organisation would look at any complaints and decide on the appropriate course of action.
Chambers did not respond to a request for comment.