Just over 27% of PSNI officers are Catholics
The SDLP has called on the government to extend the 50:50 recruitment process for the Police Service of Northern Ireland for up to 15 years.
The policy, recommended by the Patten Report, means 50% of all new recruits must be from the Catholic community.
Earlier, Security Minister Paul Goggins announced the system would end in 2011, when around 30% of police officers will be Catholics.
When it was introduced in 2001, Catholics made up about 8% of the PSNI.
That has now risen to just over 27%.
SDLP policing board member Alex Attwood said the 50:50 process needed to run for another 15 years if the PSNI is to be truly representative of the community it serves.
"Patten said one of the key tests of confidence in the police was having a balance of community representation in the police," he said.
"We need to get to 44% to have overall balance on the Catholic side. Fifty-fifty would be a key mechanism to bringing that about."
The DUP's Ian Paisley Jr said the 50-50 provisions were "discriminatory".
"It gets the back of an entire community up," he said.
"It makes people feel if you are recruited, are you recruited because of your religion?
"I think now that we have a police service that is approaching 30% Roman Catholic membership, which I welcome, I think that we now get back to the proper employment practices of employing police officers, and employing them only on merit and merit alone."
Mr Goggins said the 50:50 recruitment process had delivered "significant change".
"It has been necessary to introduce these temporary provisions in order to deal with the historic imbalance, but of course it is important that as we move forward with confidence in policing we expect applications to come from all communities, continuing to attract people of the highest calibre.
"The record number of applications for the latest recruitment competition to the PSNI underlines the growing support for the PSNI from young men and women across the community."
BBC NI Home Affairs correspondent Vincent Kearney said any extension is unlikely.
"The British government has made it clear they will not extend the 50:50 recruitment process beyond next year," he said.
"When policing and justice powers are devolved, the move would require cross-community support, so it's simply not going to happen.
"What this demonstrates is that any final agreement on devolution won't end the arguments."