A leading official in Tommy Sheridan's new party has attacked Sinn Fein for giving up the armed struggle against British rule in Ulster.

John Wight, a press officer for Solidarity, criticised Gerry Adams and Martin McGuinness for ending "the rising" against the "colonial occupation" of Northern Ireland.

Wight's comments were made in a letter to the left-wing publication Weekly Worker earlier this month.

The spin doctor, who along with Sheridan left the Scottish Socialist Party in order to form Solidarity, attacked the policies of Sinn Fein's leadership.

He criticised the party for ditching their strategy of pursuing a united Ireland by military means and signing up to the Good Friday agreement and its section on policing.

"With their recent decision to endorse and support the colonial police in the occupied Six Counties of Ireland, Sinn Fein have announced their de facto surrender to the British state," he wrote.

Wight suggested Sinn Fein would never achieve its aims without the gun: "Without recourse to military action, Sinn Fein will never be more than another tepid, social democratic formation occupying the centre-left of the political landscape."

A Solidarity spokesman said: "I wouldn't condemn John for holding those views. We are a broad movement, but Solidarity collectively don't have policies on these sorts of issues."