A man has accused former boss MP Bob Russell of sacking him unfairly.
John Scott used to work as a part-time assistant case worker at the politician's constituency office, the Chelmsford Weekly News reports.
He alleges that he was dismissed last year as a result of whistleblowing.
Mr Scott, who is in his 60s, told a pre-hearing review that his departure from the office was achieved by a breach of contract and was an example of discrimination.
A further review of the case is set to take place in October.
Mr Russell, who has been an MP for Colchester since 1997, denies the claims made against him and says they are part of a smear campaign.
He is a member of the Liberal Democrat Defence Team and a party whip and previously operated as the sports spokesman for the party.
The politician is also a long-serving member of the Home Affairs Select Committee.