Sinn Fein must offer its backing to policing reforms if they are to be successful, the oversight commissioner has said.

Speaking on Tuesday, Al Hutchinson called on the party to join the Policing Board, while encouraging unionists to support a 50-50 recruitment policy within the new service.

It is important for everyone in Ulster to "support this progress and change", he said.

"The absence of Sinn Fein, for example...leaves a gap in terms of both accountability and progress," he told the BBC.

"Equally, other parties have to support items like 50-50, registration of interest - so it is across the board.

"I am making the point that in the absence of full support, it will be an impediment to progress."

However, Sinn Fein's leaders have insisted that reforms of the police service must go further than those put forward in the Patten review.

Progress

In his first report since being appointed in December, Hutchinson reported that while an alternative to plastic bullets will not be available before next summer, he noted that neither the police nor the army has fired once since September 2002, which he described as a "notable achievement".

He also published a plan for further changes to be made within Special Branch, with a further progress report expected in September.

Assistant chief constable Roy Tonor, in charge of change management in the Police Service of Northern Ireland, insisted that many of the concerns highlighted by the commissioner had been met.

"Twelve months ago we were sitting here discussing the review of special branch - we have addressed that and are continuing to address that.

"You don't overhaul a police organisation of this size overnight.  Patten said 10 years and we are three years into it at the moment.

"Fifty-four recommendations out of 175 are completed and 63 have made substantial progress - we are steadily on the road to achieving those changes."

The study was welcomed by Northern Ireland minister Ian Pearson.

"In his overview the commissioner states that if progress continues at the present rate, the majority of the Patten recommendations will either be functionally implemented or well on the way to implementation by May 2005," he said.