In May 2021 Bob Buchan, who previously represented the Independent Union on the borough council, missed out on being one of three councillors elected in the Fens and Greatham ward to Labour’s Jennifer Elliott by 609 votes to 619.
Mr Buchan subsequently filed a petition to the High Court over claims of inaccurate information in Labour’s campaign material.
The High Court of Justice, sitting at Hartlepool Civic Centre, hear the case on Thursday, January 27, and Friday January 28.
Cllr Elliott said she will be “defending herself robustly regarding the allegations”.
Ray Martin-Wells, Hartlepool Conservatives’ Association President, who was assigned by Mr Buchan to speak on his behalf, said a letter incorrectly claimed Mr Buchan had voted in favour of a controversial 18-home development in Hill View, in Greatham, which was approved by councillors in January 2021, despite more than 100 objections.
The plans had previously been before councillors in July 2020 when they were rejected by four votes to three.
Mr Martin-Wells stated Mr Buchan was not at the second meeting and voted against the initial application.
He said: "On the balance of probability, did that leaflet change six people's minds on the way that they would vote? I think most reasonable, rational people would say of course it did.
"It is disappointing it's come to a full blown court case.
"It's regrettable that the Labour Group and the candidate decided not to address the issue early on and that it's come to this."
In response, Cllr Elliott confirmed the case would be going ahead and said: "I will be defending myself robustly against the allegations.”
She added she was unable to comment further until the case’s conclusion.
Modified plans for the houses were approved by councillors by 10 votes to one after the meeting was told that more social housing would give young people an opportunity to remain in Greatham.