The British government has been accused of trying to bully nationalists into accepting its policing reforms.
An SDLP source denied newspaper reports claiming the party had been given an ultimatum by the British government that if it did not take seats on the new Northern Ireland Police Board, reforms of the RUC would be shelved.
The source said, however, that the reports were part of a campaign to make the party accept a lesser degree of change than it felt necessary.
"The SDLP has stood up to violence and intimidation for 30 years. Any attempt to bully us through the newspapers by [Northern Secretary] Peter Mandelson will not succeed," he said.
A British government source denied the accusation that undue pressure was being exerted but warned that if the SDLP did not take up its seats on the board there would be a knock-on effect. "What we are in the business of doing is pointing out to people the reality of issues," the source said.
The British source stressed that if the new police board was not up and running by April 1st as envisaged in the legislation underpinning police reform, then reforms such as the change of the force's name, the adopting of new symbols and the induction of new recruits could not take place.
Mr Alex Attwood, of the SDLP, said his party would not be distracted from its "single-minded approach" to police reform. He said a degree of progress had been achieved since the passing of the reform legislation in Westminster but his party still required "clarity and certainty" on some issues.
He denied newspaper reports suggesting his party had demanded investigations similar to the Bloody Sunday inquiry into the deaths of solicitors Pat Finucane and Rosemary Nelson, and Robert Hamill, who was kicked to death by loyalists near an RUC vehicle. Mr Attwood said the party would not engage in "stand-and-deliver politics" and had not insisted on investigations being established before it would take its seats on the board. However, he stressed they were among the areas on which they wanted "clarity and certainty".
A British source said the government had an "open mind" on the issue of inquiries but added that "very active criminal investigations" were still under way on all three cases.