Catholic representation in the RUC stood at just eight% but the 50/50 Patten employment guidelines are intended to boost that number to bring it in line with the religious breakdown of the community as a whole.
The 50/50 principle has been criticised for "positive discrimination" and unionists are calling for its abolition, claiming that Protestant applicants are being turned away to maintain the religious balance.
The Independent Commission on Policing was formed in 1998 under the terms of the Good Friday Agreement and was chaired by former Hong Kong governor Chris Patten. The commission made 175 recommendations of change to the Royal Ulster Constabulary (RUC).
These included the appointment of an "eminent person" from overseas to supervise the report's implementation, a change to both the name and symbol of the RUC and 50/50 religious recruitment.
By September 2001, around 154 or 28% of 550 candidates were Catholic.
At present, it is estimated that 35% of all police applicants are Catholic.
This is in spite of threats to Catholic recruits from dissident republicans.
In June 2002 a young recruit in Ballymena, Co Antrim, narrowly escaped injury when an under-car booby trap device exploded as he got into his vehicle.
One month later a Catholic recruit and his family were forced out of their Newry home following threats.
However, part-time officers are not subject to the 50/50 principles and the Irish News revealed last week that the majority of new recruits 70% of 1,500 posts will be drawn from the Catholic community.
Although the SDLP, which has three assembly members on the independent Policing Board, supports the employment guidelines, unionists have called for them to be abolished.
Alliance leader David Ford claimed this week that potential police officers are joining the Metropolitan Police because of the 50/50 employment guidelines in Northern Ireland.
However, a spokesman for the Metropolitan Police said he would be surprised if their recruitment campaign had negatively impacted on applications to Northern Ireland's police service.
SDLP Policing Board member Alex Attwood dismissed Mr Ford's claims as a "lack of understanding".
Mr Ford added that Met officers who apply for a secondment to the Northern Ireland force "are being turned down because they are not Catholic".
"The same cannot be said about future secondments from the Garda where the 50/50 quota does not apply. As it is only about three% Protestant this leaves the government open to yet further accusations of discrimination," he added.
Mr Attwood, however, said 50/50 was and would continue to be the basis for recruitment, adding that recruits are being trained to "an extremely high standard".
"If there are so many officers going to England why is it that 14 from the Metropolitan police have gone into the PSNI?
"David Ford should go and speak to people who know what's going on rather than speaking about things he doesn't understand."
Meanwhile, North Down Ulster Unionist MP Lady Sylvia Hermon added her voice to that of Mr Ford.
She claimed that the British government was legalising discrimination in its drive to boost Catholic numbers in the force.
"Young Catholics are warmly welcomed in the new police service for Northern Ireland, and I am pleased to see them there. But I am deeply concerned about the possibility of their being made to feel that they are not there on merit, but because of their religion," she said.