In the opening of its New Beginning to Policing document yesterday, the SDLP leadership said policing has been at the heart of the "political fault line" in Northern society since 1920.

"No issue has been more difficult, more divisive and more controversial in the history of the North of Ireland," the statement said.

With the support of the Taoiseach and the Catholic hierarchy, the SDLP has taken a high risk political step - from a nationalist perspective - of supporting policing structures in Northern Ireland.

It was a historic departure set in the former unionist bastion of the Stormont Parliament building. It also showed that after years of turbulent, painstakingly slow progress, the Northern "peace process" is producing real evidence of the new "dispensation".

In the party's history it was as significant as its decision not to join the power-sharing assembly of 1982 despite pressure to do so from the Republic's government and hierarchy. That decision prevented the party from being sucked into a permanent minority status in a new Stormont.

There is now power-sharing; there are major human rights and equality structures in the North outlawing discrimination, and nationalists are patently enjoying better standards of living.

It has been a long road since John Hume set out on the path of change through civil rights agitation to constitutional politics in Derry in the late 1960s when decades of unionist discrimination had contributed to Catholic alienation, unemployment and poverty.

In recent years the SDLP has suffered isolation and suffered electoral setbacks, losing its position as the majority nationalist party.

Yesterday's decision is, primarily, a vital nationalist endorsement of the creation of an impartial police force to impose law and order in Northern Ireland.

So long as this does not exist republican and loyalist paramilitaries will fill the vacuum. Murder, punishment-beatings, possession and training in firearms and explosives is the permanent alternative to the creation and support of a new police force.

The SDLP was able to say yesterday that after 2 1/2 years of work it had managed to prise key concessions from the British government. It also said it had caused the retraction of the amendments to the Patten Report which had been inserted by the previous Secretary of State, Mr Peter Mandelson, to assuage unionists.

The acting Deputy First Minister, Seamus Mallon - in his usual pithy manner - pointed out that the SDLP had won the reversal of the pro-unionist amendments inserted into the Police Bill 2000 by Mr Mandelson. The legislation, Mr Mallon said, had been "Mandelised". That had now been fixed. It had been "deMandelised".

Mr Mallon pointed out that within a relatively short period of the appointment of the Policing Board - sans Sinn Fein - the Secretary of State for Northern Ireland will direct the changes to the name, flag and badge. The new Oversight Commissioner will recommend changes to the current policing legislation.

The SDLP also stated that it had achieved agreement from the British government to amend the current policing legislation to deal with key SDLP concerns: the strengthening of the powers of inquiry of the Policing Board; an enhanced role for the Policing Board - which will enjoy powers formerly resting with the Chief Constable and the Secretary of State; new powers for the Police Ombudsman to access documents and investigate police policies and practices; commitment to the secondment of gardai to the new police service; strengthened commitment to human rights; greater focus on community policing; phasing out of the full-time reserve; and expansion of the part-time reserve ahead of Patten's schedule.

The SDLP also says that being on the Policing Board will allow them to campaign more effectively for a prohibition on plastic bullets.

They point out that Patten did not recommend the banning of plastic bullets: "On the board we will have full access to the research, which will help us to make the case for prohibition of these weapons."

Under the previous legislation the British government attempted to give the Chief Constable and the Secretary of State the power to block inquiries on "efficiency and effectiveness; the administration of justice; repetitiousness and vexatiousness; ongoing investigations by the police and other authorities; or because an inquiry would serve no useful purpose".

The SDLP was able to announce yesterday: "These sweeping exemptions would have meant that the Policing Board could only have conducted inquiries at the grace and favour of the Chief Constable and the Secretary of State. Now, all of these exemptions have been abolished".

The new proposals also reduce the size of the majority needed for the 19-member board to order an inquiry from 12 to 10.

The SDLP pointed out that the Patten report was strong in its recommendations on the inclusion of human rights safeguards, stating that the fundamental purpose of policing should be the protection and vindication of the human rights of all".

The British government's original plans did not reflect this strong commitment to human rights, the SDLP said. Now, "the Police Board - not the Chief Constable - will have the final say on the training, education and development strategy for the new police service".

The SDLP was also able to promise that secondments of gardai to the new police service in specialist areas "will begin forthwith" in order to make up a shortfall in Catholics that will continue even with 50/50 recruitment.

There will also be the formal treaty to ensure that gardai who are seconded should suffer no financial detriment; that gardai will be encouraged to work in the North and the experience obtained will be fully recognised; the new police service will engage in outreach with the Garda; secondments should be possible at all levels above inspector; qualifications and experience of gardai will be fully recognised.

The other contentious issue was the reform of the RUC Special Branch. "The SDLP shares Patten's view that Special Branch is a `force within a force'. In line with Patten, police officers are not to spend more than five to seven years in Special Branch. This is critical to end the `force within a force'."

Originally, the British government only committed itself to review the timing for the implementation of Patten's crucial recommendations on the Special Branch. But now, in line with Patten, the Special Branch is already under one Assistant Chief Constable. It has already been reduced by 10 per cent and it is to be reduced to 50 per cent in September, with amalgamation of support units into the wider police service.

Jim Cusack is Security Editor of The Irish Times