The Soviet Union's second-ranking official said here today "it is now up to the United States to make a move" if forthcoming talks between the two superpowers on trying to set a new arms control agenda are to get anywhere.

In an unprecedented address by a high-level Soviet official to a British parliamentary body, visiting Politburo member Mikhail Gorbachev told Parliament's foreign affairs committee that the Reagan administration also should "take, this time, a realistic stand which would make for effective negotiations" at any future talks.

While Gorbachev's week-long trip here, now in its fourth day, has focused on U.S.-Soviet arms talks scheduled for January, his visit has been viewed as helping to improve British-Soviet relations and mutual understanding. His visit is seen as a considerable public relations success.

Today, however, Gorbachev showed his first flashes of irritation during the private session with the British parliamentary committee, when he was questioned about human rights issues and religious persecution in the Soviet Union.

The committee chairman, Anthony Kershaw, told reporters later that Gorbachev replied, "I can quote a few facts about human rights in the United Kingdom. For example, you persecute entire communities, nationalities." The legislators assumed he was referring to Northern Ireland.

Gorbachev said Britain had 2.3 million unemployed and added, "You govern your society and you leave us to govern ours."

Other committee members said they thought Gorbachev overreacted and was too defensive. Besides, one added, the actual unemployment figure is more than 3 million.

Member of Parliament Norman St. John-Stevas, who questioned Gorbachev on human rights, said the response was "electrifying. Up to then," he said of the committee session, everything had been "quite matey. Suddenly, he [Gorbachev] sprang to life when I raised the question of religious persecution of religious minorities -- Christians, Jews and Moslems -- and pointed out to him this was a major obstacle in the way of better Anglo-Soviet relations. What I got was a 15-minute reply that ranged over Russian history and which claimed there was no persecution in the Soviet Union," St. John-Stevas said. "Clearly Gorbachev and the others are extremely sensitive on this issue."

The delegation led by Gorbachev has made clear that shutting off the U.S. effort to develop a variety of defensive space weaponry is Moscow's top priority in future negotiations.

Yesterday, according to accounts of private meetings with the British foreign minister provided by British sources, Gorbachev emphasized his concerns about Reagan's so-called "Star Wars" plan to research the prospects for a space-based defense against missile attack.

Today, there was heavy emphasis also on U.S. plans to test an anti-satellite weapon.

The Soviets already have such a weapon.

At the same time, a member of Gorbachev's entourage warned today that "complexities will develop" if the United States does not come to some understanding with Moscow on antisatellite weapons before the United States makes a scheduled test of such a weapon in March.

The statement by Evgeni Velikhov, the top Soviet space expert and a vice president of the USSR Academy of Sciences, struck committee chairman Kershaw as "in a way, a threat to say it's too late after March."

The Soviet statements are a prelude to talks on Jan. 6 and 7 in Geneva between U.S. Secretary of State George P. Shultz and Soviet Foreign Minister Andrei Gromyko. They are to discuss ways to renew talks on limiting nuclear arms that have been broken off since last year, when the Soviets walked out of two sets of talks on strategic and intermediate-range missiles.

In his remarks today to the committee, Gorbachev suggested that those earlier talks are now officially buried in the Soviet view. He described the Soviet initiative to meet again in Geneva as a start on "entirely new talks which would embrace the question of the non-militarization of space and questions of reducing nuclear arms, both strategic and medium range."

"Of key importance in all this," he said, "is the prevention of a space arms race. Such a race would not only be dangerous in itself, it would give a boost to the arms race in other areas," he said, apparently alluding to the prospect of adding more missiles to overcome any space-based defense.

[In Washington, White House press secretary Larry Speakes, said, "We're willing to participate in talks that will lead to the reduction in space weapons. . . . We're willing to listen to whatever they have to say," United Press International reported.]

Gorbachev's suggestion that it is now up to Washington to make the first move in new talks contrasts with the recently published views of a member of the U.S. arms delegation to Geneva, retired Lt. Gen. Edward Rowny, who suggested that the United States should let Moscow make the first move.

According to foreign diplomats and published reports, the Reagan administration has yet to make a final decision on how it will approach these discussions.