The Provisional Irish Republican Army today rejected the impassioned plea by Pope John Paull II last weekend in Ireland that the IRA stop its campaign of violence in British-ruled Northern Ireland.

"In all conscience," the provisional IRA said in a statement, "we believe that force is by far the only means of removing the evil of British presence in Ireland."

The statement was issued to reporters in Belfast just an hour after leaders of the Provisional IRA's political arm told reporters at a press conference in Dublin that they would like to meet with the pope to discuss this peace plea. But, they, too, said there could be no cease-fire until British troops were withdrawn from Ulster.

At the same time, the British government revealed that it was trying a new political initiative in Northern Ireland and that its retired chief of counterintelligence would take over coordination of security forces there.

Britain's Northern Ireland secretary, Humphrey Atkins, said today in Ulster that a plan for some form of home rule there may be introduced in the British Parliament soon. He has been discussing this with Protestant and Catholic leaders in Northern Ireland in recent weeks and met with more of them today.

British officials would not discuss details, but Atkins implied that specific proposals already have been discussed by Prime Minister Margaret Thatcher's Cabinet. One British official said the government hoped to have a plan ready for Parliament "within a couple of months."

The British have been urged by Irish Prime Minister Jack Lynch to establish a home rule assembly in Northern Ireland in which the Protestant majority and Catholic minority could share power. After the assassination of Lord Mountbatten in August, Lynch told Thatcher that Ireland would no longer insist that formal assurances or mechanisms for the eventual unification of Ireland be included in an Ulster home rule plan.

A power-sharing executive arrangement tried in Ulster in 1974 collapsed after Britain, in a concession to Ireland, agreed that the Ulster executive's members also would sit with Irish government representatives on a "Council of Ireland" with vague cross-border powers. Opposing this as the beginning of eventual unification of Ulster and Ireland, Protestants in Northern Ireland staged a massive general strike that scuttled the power-sharing executive a few months after it came into being.

Thatcher has given Atkins primary responsibility for the new political initiative in Ulster. But she had decided to turn over supervision of the security forces in Ulster to a new civilian coordinator, Sir Maurice Oldfield, the retired director of Britain's secret intelligence service.

Oldfield, as head of MI6, the counterspy service made famous by the novels of Ian Fleming and John Le Carre, is reputed to be the man on whom Fleming based the spy chief "M" in his James Bond thrillers and on whom Le Carre based the character "Smiley" in "Tinker, Tailor, Soldier, Spy," currently being dramatized on BBC television here.

He will decide strategy for the fight against IRA terrorism and coordinate operations of the Royal Ulster Constabulary and the 13,000 British soldiers stationed in Northern Ireland. There has been friction between Army and police officials since the British began shifting the primary responsibility for day-to-day security from the soldiers to the police in process referred to here as "ulsterization."

The conflict broke out into the open after the murder of Lord Mountbatten and 18 soldiers on the same day in August. The Army and the police disagreed over priorities for changes to be made in security strategy. Atkins also was criticized by some Ulster and British politicians for ineffective leadership of the security forces since being named Northern Ireland secretary in May.

Oldfield, according to the announcement of his appointment today, will be responsible for "improving the effectiveness of the fight against terrorism in Northern Ireland." He will be based in Ulster and will have the support of an around-the-clock staff of Army, Police and civilian officials.

Nearly 2,000 people have been killed in the sectarian violence in Northern Ireland since British troops were sent there 10 years ago. Recently, after its ranks were decimated by infiltration and arrests, the Provisional IRA reorganized itself into a leaner, more successful in killing members of the security forces and selected "symbolic" targets like Lord Mountbatten.

During his visit to Ireland over the weekend, the pope won enthusiastic support from Irish Catholics for his strongly worded condemnation of terrorism in Ulster. "On my knees," he said to the IRA and its supporters, "I beg you to turn away from the paths of violence and to return to the ways of peace."

The Provisional IRA answered in its statement today that "the roots of the present troubles have their source in social and economic deprivation" for which it blamed Ulster's Protestant majority and the British government.

"Church leaders, politicians and establishments are bankrupt and have failed to resolve the social and economic problems suffered by our people," the statement said.

The Provisional IRA's political leaders said in their press conference in Dublin that they would like to meet with the pope to discuss "the Irish struggle for independence." They said his "genuine interest in achieving true peace based on justice is warmly appreciated."

But they said there could be no peace until the British withdrew from Ulster, gave all terrorists amnesty and agreed to "Irish self-determination" there.