The Police Authority for Northern Ireland said a compulsory register of interests would strengthen public confidence in the RUC's independence and impartiality.

The force has been one of the principal targets of republican terrorists because it is seen as having a bias towards the unionist community.

Police Authority: "Real fears" of terrorist attacks

The call came as debate intensified over the future of the force and as the government prepared to establish a Policing Commission, headed by former Governor of Hong Kong, Chris Patten. This will draw up reforms as part of the Good Friday Agreement.

There has been resistance within the RUC to the idea of a register listing officers' membership of groups such as the Freemasons, the exclusively Protestant Orange Order and Apprentice Boys or the Catholic Ancient Order of Hibernians.

Plastic bullets to stay

They argue it would place officers at greater risk of terrorist attack as well as infringing on their personal liberty.

But the report stated: "The Authority understands these very real fears but still concludes that it would be in the wider interests of the police service to make it a requirement on all police officers to register their membership of all outside organisations."

Officers' security could be protected, it suggested, by opening the register to the scrutiny of an independent inspector, rather than making it public - for the time being.

The report also challenged established conventions in the force, such as the display of the Union Flag at RUC stations.

'Reshape the police service'

But it came out in favour of the force keeping its name - while qualifying it with the sub-heading: "Northern Ireland Police Service".

It also recommended no changes to the existing bottle green uniform and the RUC emblem of the harp and crown.

The authority also considered the use of plastic bullets - which nationalists have long campaigned against - and concluded "with some reluctance" that there was no effective substitute for the weapons in large-scale disturbances.

The publication of the report also saw the authority chairman extend a fresh invitation for talks with the nationalist parties which have so far boycotted it.

Police Authority chairman Pat Armstrong said Sinn Fein and the SDLP should contribute to discussions on the future of policing in Northern Ireland.

"We now have a chance to reshape the police service for the benefit of everyone and to build a prosperous and peaceful new society - a fitting tribute to all those who have sacrificed so much in the past," he said.

"I would urge everyone to have the courage to grasp this rare opportunity."