Zambian President Kenneth Kaunda, warning against Britain's using "dirty tactics" in bringing about Rhodesian independence, opened talks today with British Prime Minister Margaret Thatcher and Patriotic Front guerrilla leaders in an effort to resolve stalled peace negotiations.

Despite British efforts to push the Patriotic Front to accept transitional arrangements leading to independence, the nine-week-old conference marked time while Kaunda apparently sought to mediate the differences between the guerrillas and Britain. The Salisbury government of Prime Minister Abel Muzorewa has already accepted the British proposals.

There was a temporary flurry at the conference today when the Patriotic Front failed to show up for scheduled talks, an action British Foreign Secretary Lord Carrington terms a "discourtesy," strong words for a British diplomat.

The British knew that Front leaders Robert Mugabe and Joshua Nkomo were meeting at the time with Kaunda, according to Zambian sources.

The sources called the British pique "childish" and said Britain could hardly expect the Front to provide a response before Kaunda, a key supporter of the guerrillas who had been instrumental in setting up the conference, completed his talks.

After meeting with the Front, Kaunda talked with Thatcher and attended a dinner in his honor given by the prime minister, Zambian officials said further talks were expected tomorrow and possibly Saturday.

In an interview aboard his flight to London, Kaunda warned that Britain must carry out elections in "a fair and just manner" and that imposing Muzorewa through "dirty tactics" such as quick elections would not work.

"It is none of my business to install the Patriotic Front in power and none of Britain's business to install Muzorewa in power," he said.

He declined to talk about what he would propose to Thatcher, saying he was first going to listen to her and then see what can be done to bring about a solution.

Kaunda, whose country has suffered repeated Rhodesian military attacks in the last year, said "We cannot afford to fail." He declined repeatedly, however, to say that he was optimistic about the outcome of the visit.

The three key issues he said he would take up with the British are: the length of the transition period, his suggestion for a Commonwealth force to maintain the cease-fire and the need for all sides in the election to be given equal status during the campaign.

Kaunda has backed the Patriotic Front's demand for a six-month transition period while Britain has stuck to two months, although indicating some flexibility was possible. Time to campaign is important to the Front since it has been banned inside Rhodesia and hundreds of thousands of its supporters are refugees in neighboring countries.

On the security issue he said Britain's plan to have the present Rhodesian police maintain law and order was "completely unacceptable."

"I can't understand what Britain intends to do" on the peacekeeping issue, he said, adding that some incidents of violence would be inevitable during the election campaign, especiallly under Britain's proposal which excludes armed peacekeeping forces.

He was also concerned that although the Muzorewa government would step down under the British plan, officials would keep their perquisites of office such as government housing, vehicles and funds, which would give them an unfair advantage in the election.