Des Long said South, killed in an IRA attack on the police station in Brookeborough, Co Fermanagh, 50 years ago this this week, had adhered to traditional republican values.

"He went to his death with the expectation that his sacrifice would be rewarded by a united Ireland. Sean South did not die to reform the RUC nor to take part in overseeing the police. He died in the cause of Irish freedom and the fight against British rule in Ireland.

"It gives me no pleasure to say that former comrades are now working in the interests of upholding and enhancing British rule in part of Ireland, " Long continued. "The latest moves by Martin McGuinness and those around him to recognise the police is akin to siding with the force that killed Sean South."

Long, a former Republican Sinn Fein vice president, accused the Provisional movement of surrender.

"McGuinness should act with some honour and stay away from the grave of Sean South."