Keith Gray, who wants to be a Labour candidate, has instructed KRW LAW LLP to challenge the party’s long-standing position of only running in Great Britain.

Lawyers for Mr Gray have sent a pre-action protocol letter to David Evans, the party’s general secretary, to put Labour on notice of Mr Gray’s intention to bring the matter to the High Court.

The High Court will be asked to rule that the party is in breach of its contract with Mr Gray on the grounds of discrimination and is acting in bad faith in not fielding Labour candidates at elections in Northern Ireland.

In addition, Mr Gray maintains that Labour’s policy is also in breach of that contract as being incompatible with Article 21 of the Universal Declaration of Human Rights, which is to be implied into the contract.

Further, the policy denies Mr Gray his rights under Article 10 of the European Convention on Human Rights (ECHR) which secures the right to freedom of expression.

Mr Gray said: “I am a proud member of the Labour Party. I want to be able to elect Labour Party candidates to local councils, Stormont and Westminster. I want to be able to put myself up for candidature.

“The SDLP is not a ‘sister-party’ as the NEC and leadership say it is. SDLP policies are not the policies of the Labour Party.

“For too long members of the Labour Party have been discriminated against and the trust between them and the Labour Party has been broken. Now is the time for a challenge.”