An MP is taking the Labour Party to court over its decision to reinstate his suspension for his remarks about the party's handling of anti-Semitism.
Chris Williamson had claimed the party was "too apologetic" on anti-Semitism.
His original suspension was lifted in June following a formal warning, but it was reimposed two days later after a backlash from Jewish groups.
Mr Williamson said he hoped to overturn the "unconstitutional" decision to "re-suspend me from the party I love".
Mr Williamson, who has lodged legal papers with the High Court, tweeted that he had "dedicated my life to the Labour Party since I was 19-years-old, and I'm 63 next month".
A Labour spokeswoman said the Derby North MP's case had been referred to the National Constitutional Committee - the party's highest disciplinary body.
He was suspended in February after being filmed saying Labour "had given too much ground" and was being demonised over anti-Semitism complaints.
He later said he "deeply" regretted the remarks.
In July, a panel of Labour's National Executive Committee ruled that Mr Williamson should be allowed back into the party.
However, a large outcry from Labour peers and MPs saw the suspension reinstated.
A campaign group has been attempting to crowdfund £75,000 to support Mr Williamson's legal bid.