Pakistani opposition leader Benazir Bhutto is reluctant to force a direct confrontation with the government in her campaign to remove President Mohammed Zia ul-Haq, according to one of her senior aides.

Following the normal political lull during the Moslem month of fasting, Ramadan, which ended last week, Bhutto is scheduled to resume the rallies and motorcades she began after returning from exile in April. Several factors, including Bhutto's declared aim of forcing Zia to hold national elections this fall, had led many political observers to predict last month that Bhutto's campaign would become more aggressive and confrontational after Ramadan than the vocal but passive rallies she has held so far.

However, Bhutto's Pakistan People's Party and the broad alliance of opposition parties it heads are both preoccupied with unresolved internal differences. Political observers here and in Islamabad also believe Bhutto may question whether she can now mount a sufficiently massive and organized campaign to challenge the government directly.

Bhutto called Saturday for peaceful demonstrations throughout Pakistan July 5 to demand national elections this fall, The Associated Press reported.

Even if Bhutto now seems inclined to limit herself to public meetings demanding Zia's resignation, independent analysts and Bhutto's associates agree that she will face increasing pressure to shift to tactics, such as strikes or civil disobedience, that might lead to violent conflict with the authorities. Many Pakistanis fear that any such conflict would set back their country's cautious evolution from martial law toward a civilian parliamentary system.

Zia overthrew Benazir's Bhutto's father, prime minister Zulfiqar Ali Bhutto, in 1977 and later allowed his execution. Zia ended more than eight years of martial law in December and declared himself the civilian president until 1990. Benazir Bhutto challenges the legitimacy of hs presidency and that of the civilian government that now administers the country under him.

In her campaign, Bhutto "does not feel that the stage for confrontation has been reached," according to Rao Rashid, a senior official of the People's Party. "Miss Benazir's activity will be the same as before," he said in an interview here. Rashid, a member of the party's central executive committee, said Bhutto will work on building her contacts with specific groups, including students and organized labor.

"Once she has shown that there will be no subsiding of her popularity, maybe they the government will listen to reason," Rashid said.

Rashid, and Bhutto herself, explained her cautious strategy so far as motivated by a desire to avoid provoking the government into violence, although at other times, Bhutto has said she would force the government "to concede our demands or repress us." Independent observers suggested that Bhutto's caution is due at least partly to the uncertainties of her own position.

With the massive crowds at her rallies, Benazir Bhutto "has established herself as an important political figure, but she has not shown that she could direct them to bring down the government," a political reporter for a Pakistani newspaper said here.

Bhutto, who inherited the chairmanship of the party from her ailing mother while in exile, still finds herself largely occupied with establishing control over the party's apparatus. She faces a challenge within the party from some older leaders who were close associates of her father "and who do not like to be dictated to by a beginner like Benazir," the Pakistani journalist said.

A number of older party figures have shown support for Ghulam Mustafa Jatoi, whom Bhutto removed as party leader in the southern province of Sind. Jatoi is seen as having strong organizational support within the party, and, according to Pakistani press reports, has been meeting in London with various party figures to discuss a coordinated challenge to Bhutto's leadership.

Disagreements also remain between the People's Party and many of the smaller parties of the opposition umbrella alliance, the Movement for the Restoration of Democracy, about coordinating the challenge to Zia.

The smaller parties "realize that, in an election, they would be swamped by the People's Party," said Mazhar Ali Khan, editor of a weekly political magazine. "They are asking for a formal electoral alliance, which really means they are bargaining for a guaranteed number of places on a joint ticket."

Bhutto and the People's Party have resisted any electoral alliance or other expansion of the loosely bound opposition movement that might force it to limit its freedom of action.

The leaders of the 11-party alliance are to meet in Islamabad June 19 for the first time since Bhutto's return in what several observers suggested will be an important test of its cohesion.

The 11 parties of the fragile alliance agree on almost nothing other than their opposition to Zia. Observers disagree over how badly a breakup of the coalition would hurt Bhutto's campaign, but Khan said it would hand Zia an important psychological weapon to exploit against the opposition.

During Ramadan, while Bhutto focused on meetings with party and opposition figures, Zia reinforced his warnings against any escalation of her public campaign. He repeated that he will not consider any elections before 1990, as demanded by Bhutto, declaring, "We will not allow our nine years of hard work to go to waste, nor will we permit anyone, having lust for power, to prematurely impose oneself on the people of Pakistan."