The prospect of an imminent showdown between opposition leader Ayatollah Ruhollah Khomeini and Prime Minister Shahpour Bakhtiar receded at least for the time being today as the Moslem cleric sought to use political pressure to achieve a peaceful takeover.

As the initial tumult over Khomeini's return from exile began to subside, the political struggle moved from the streets to the country's parliament where Khomeini was trying to encourage massive defections and thus deny the government its legal base.

With about 70 deputies in the 282-seat Majlis already having quit, Khomeini needed 65 more resignations to reduce the lower house to less than half, presumably forcing Bakhtiar's resignation for the lack of parliamentary support.

Earlier this morning Khomeini said at a press conference that he would announce a provisional government shortly unless Bakhtiar resigned and would go ahead with plans for a referendum to set up an Islamic republic. Although this is the first time Khomeini has made such claims in Iran he has made similar statements from Paris.

Friday's political maneuvering also brought to light divisions in the opposition camp over tactical approaches to the current crisis. A possible secret deal between Khomeini and the armed forces chiefs is not ruled out by Bakhtiar supporters who view it as the greatest threat to the government.

Khomeini's ultimate goad to Bakhtiar still is the unspoken threat of a Jihad (holy war), and the acid test of the struggling government still will come if the ayatollah proclaims a provisional government. But notwithstanding rhetoric emanating from hardline supporters just arrived from Paris, the tone Friday was one of relative moderation.

The moderation, however, did not go so far as meeting Bakhtiar, who again Friday proposed an "exchange of views" with the cleric.

Reacting to reports that two top aides had asked the prime minister for a meeting, Khomeini said through a spokesman, "Those who say I have attempted to contact Bakhtiar were liars. It is not true. It is an absolute lie that I ever tried to contact him."

Khomeini repeatedly has said he will not meet Bakhtiar until the prime minister resigns.

At Khomeini's makeshift headquarters in a former girls' school near parliament, an aide said the Shiite Moslem leader wanted to wait until more members of the parliament and the regency council appointed by the nowabsent Shah Mohammad Reza Pahlavi resigned, in hopes of achieving a new Islamic government without further bloodshed.

Hossein Bani-Assadi, the aide, announced Friday that 40 members of the Majlis, the lower house of parliament, resigned on the day of Khomeini's triumphal return. Thirty Majlis deputies previously had quit.

Bani Assadi said if enough members resign, "there won't be any parliament any longer. The government will have no legal base. The Cabinet will have to resign, too.

"This is the best solution. It will avoid bloodshed and confrontation," he said at a news conference.

It is unclear, however, whether such massive resignations would automatically make the Cabinet invalid, whether Bakhtiar would step aside or whether perhaps he would be forced to call a new general election.

Bani-Assadi also disclosed that a second member of the nine-member regency council named by the shah, Abdol Hossein Aliabadi, resigned three weeks ago but declined to make it public. Bani-Assadi said another member, whom he did not identify, has not appeared in public recently and may soon quit the council.

For his part, Bakhtiar also appears to have settled in for a protracted test of strength with Khomeini, in hopes that either moderate elements in the opposition will draw the ayatollah closer to a political compromise, or that Khomeini's return will deepen divisions in his camp and slow down the momentum of the Islamic government movement.

A highly placed Iranian governmetn source said Bakhtiar's strategy is to let Khomeini keep talking and let him proclaim his "government in exile at home," while more moderate Moslem leaders grow increasingly disenchanted. The official noted that three important ayatollahs from Qom, the holy city, did not appear at Tehran's international airport for Khomeini's return from Paris Thursday.

Among those conspicuously missing was Qom's Ayatollah Kezem Shariatmadari, who has said he is waiting for more information about the revolutionary council before voicing an opinion.

Bakhtiar was said to be confident of the loyalty of the armed forces, and to have warned that those elements that defect will be dealt with harshly.

There have been recurring reports of mutinies, sabotage of warplanes, desertions and refusal by noncommissioned officers and enlisted men to obey orders -- reportedly resulting in summary executions. During anti-shah demonstrations some soldiers expressed in various ways sympathy for Khomeini's cause.

More significantly, top generals, including the chief of the supreme commander's staff, Gen. Abbas Gharabaghi, have continued to negotiate with Khomeini's staff. The military's last line of defense -- negotiations -- appears to have been predicated on a conclusion that they would rather have Khomeini in Iran, where a moderate influence can be exerted, than have him direct massive protests from his Paris headquarters.

But from Bakhtiar's vantage point, a deal between Khomeini and the military would seem to pose the greatest single threat to the government.

Bani-Assadi Friday expressed gratitude to the armed forces for its treatment of Khomeini during his homecoming, which included an air force guard at the airport and a military helicopter used to ferry the ayatollah the last leg of his parade route to the cemetery.

"We take that as a gesture of being conciliatory," said Bani-Assadi, who is associated with Mehdi Bazargan, Khomeini's chief strategist in Iran.

He said Khomeini's entourage was "more optimistic than pessimistic" about chances of an agreement with the military.

A crowd of thousands of persons, mostly men, crowded around the Alhavi school Friday morning for a glimpse of the ayatollah, who came to the window and gestured his blessings without speaking.

Later the crowd was replaced with a number of women, most wearing the chador, a full-length black veil, who chanted their support of Khomeini until he came to the window and gave his blessing.

Khomeini's aides said the ayatollah went to bed about 11:30 p.m. Thursday night after his trip from Paris and was up at 3 a.m. Friday doing paper work until 5:30 a.m. prayers.

The headquarters was bedecked with posters depicting the new Islamic republic flag, and on one building were pinned color photographs of mutilated bodies that the opposition said were victims of the Iranian Army troops.