Kingsmill Inquest: Beattie seeks Justice Minister Naomi Long's view on Sinn Fein conduct

The UUP leader has also written to the Secretary of State for Northern Ireland following the findings of the coroner at the conclusion of the inquest into the Kingsmill massacre of 1976.

In a letter to the Secretary of State, Mr Beattie outlined his concerns at the coroners' findings – in particular, issues surrounding the transparency of the evidence given by the Irish Government.

In his letter, Mr. Beattie said it was deeply concerning that the victims and their solicitors were not allowed to be present when this evidence, heavily redacted, was presented.

The party said he also highlighted the much wider-reaching issues concerning Sinn Féin's failure to give evidence to the inquest – including commitments under the Ministerial Code and Pledge of Office – which states: “To uphold the rule of law based as it is on the fundamental principle of fairness, impartiality and democratic accountability, including support for policing and the courts as set out in paragraph 6 of the St Andrews Agreement”.

He has asked the Justice Minister Naomi Long for her ruling on this issue. In particular, he has asked whether she has concerns around the “disregard for the Courts shown by Sinn Fein” and what action is available to her to deal with this issue.

The UUP said “No political party or politician should be allowed to show the courts such a flagrant disregard. Sinn Fein had a duty to engage positively with this court process and the Irish Government must be more transparent when dealing with issues surrounding our troubled past.

“Only a United Kingdom Government inquiry, made public, can address these issues. It will ensure our collective government can continue in the spirit of cooperation and collaboration with political parties upholding their commitments”.

Sinn Fein have been approached for comment.