With donnish dignity undisturbed by the scandal swirling around him, Anthony Blunt, eminent former art curator for Britian's royal family, today described his secret life as a Soviet spy.

Emerging from seclusion to paint a revealing if somewhat shaded self-portrait of a spy, the tall, distinguished-looking 72-year-old art historian explained why he had betrayed his country. "I believe it was the right thing in the cause of anti-fascism" during the dark days before and during World War II, he said.

"I realize I made an appalling mistake," Blunt said, his long patrician face and deep, aristocratic voice showing no emotion. "I now realize bitterly that this was totally wrong."

But, he steadfastly maintained, "I feel I haven't betrayed my conscience." When he was recruited into the service of the Soviet Union by his close friend Guy Burgess at Cambridge University in the mid-1930s, Blunt said, "I was persuaded that I could best serve the cause of anti-fasciam by joining him in his work for the Russians. This was a case of political conscience against loyalty to country. I chose conscience."

In a series of televised interviews with selected British journalists here, Blunt admitted that he acted as a "talent-spotter" for the Soviets while teaching at Cambridge during the late 1930s and passed secrets to Moscow while working as a British Intelligence agent during the war.

He said he remained in contact with other Soviet spies inside the British government after the war while personally serving first King George VI and then Queen Elizabeth II as curator of the vast royal art collection. Blunt acknowledged helping friends and fellow spies Burgess and Donald Maclean escape to the Soviet Union in 1951, and revealed that he refused an order from Russia to leave Britain with them.

After secretly confession his crimes to British officials in exchange for immunity from prosecution in 1964, Blunt gave them information about still more spies in the British establishment, including some still living here.

"My guess would be that there must have been a great many more people involved in this," he said. "I must shut up on this, but I think it is common knowledge that the network was considerable."

While the British Attorney General, Sir Michael Havers, said today that Blunt was given immunity on the authority of the then attorney general, the late Sir John Hobson, Blunt said, "I was told it was made under higher authority. I wouldn't like to be too specific about this, but my impression quite certainly was that it was the [then] Prime Minister," Sir Alec Douglas-Home. Lord Home has said he does not remember being told.

But Blunt said he believed the queen, who had knighted him in 1956, was not immediately informed and Blunt remained on her staff until last year. His total period of royal service spanned three decades. He said he thought that she or her private secretary may finally have been told about his past in 1972, when "I rushed to hospital for a very serious cancer operation which it was thought I wouldn't survive."

The queen stripped Blunt of his knighthood, the Royal Victorian Order for personal service to the royal family, immediately after Prime Minister Margaret Thatcher unmasked Blunt's past as a spy in a statement to Parliament last week.

Today, to cheers from both government and opposition benches in the House of Commons, she announced that she was killing a controversial "protection of official information" bill that would have tightened Britian's already strict secrecy laws. A chorus of critics had argued that the pending legislation would have prevented publication of the recent book by author Andrew Boyle, "The Climate of Treason," that hinted at Blunt's Blunt's identity as the "fourth man" in the spy ring of Burgess, Maclean and Kim Philby.

However, Thatcher told Parliament that she still believed that British intelligence services must "have a very considerable element of secrecy." It is likely that the present Official Secrets Act will remain in force and that Thatcher will introduce amendments to narrow its sweeping scope.

The House of Commons will examine the Blunt case and its wider implications in a extraordinary all-day debate Wednesday which Thatcher will open with an additional statement on the affair. Blunt himself helped widen the field for the debate with his statements today about other spies and high-level approval of his immunity deal.

Although he was in tears while leaving The Times Newspapers building where he gave the interviews, Blunt remained almost impassive throughout the questioning. As he slumped comfortably in a easy chair, his light blue eyes stared unblinkingly at interviewers who asked pointedly about his homosexuality, his treason, his present feelings and his future plans.

Blunt, a brilliant, well-connected clergyman's son who attended the best schools, first studying mathematics but eventually becoming one of the world's leading arts experts, never denied his homosexuality. But he strongly denied having a homosexual relationship with Burgess, a flamboyant homosexual whom Blunt met at Cambridge's prestigious Trinity College.

After being persuaded by Burgess to become a soviet agent and helping the Soviet spot other candidates at Cambridge, Blunt said, he was recruited by the British government into its wartime intelligence service despite his well-known Marxist sympathies. Many young British intellectuals, like their contemporaries in the United States, were attracted to communism in the 1930s, party as a reaction to the Nazi threat in Europe.

Blunt insisted that the secrets he passed both to Burgess and to a Russian diplomat here during the war consisted mostly of British intelligence about the Germans, rather that information that could have compromised British secret agents. Asked if he could have caused the deaths of any British agents, Blunt, said, "The answer to that is categorically no."

He described his gradually shifting loyalties among Britian, the Soviet Union and his circle of traitorous friends.After the war, he said, he became disillusioned with the Soviets and communism. But he remained loyal to and in contact with his friends in Moscow's employ, even after he went to work for the queen.

Blunt denied that he tipped off Maclean that British officials were closing in on him, but he admitted helping, at the request of Burgess, to arrange the escape of Burgess and Maclean in Moscow in 1951. Blunt disobeyed a Soviet order to go with them, he said, because by then "I couldn't bear the thought of living in Russia and preferred to take the risk of going on here."

Although suspicious British officials questioned him repeatedly during the next decade, Blunt admitted nothing until presented in 1964 with new information that "freed me from my loyalty" to friends. He said he could not divulge the information, but hinted that it referred to other Soviet spies still in Britian.

He said he was offered immunity from prosecution without asking for it, and he cooperated by naming other wartime spies here in interviews with the authorities that stretched into 1965.

When asked if he was treated more leniently than other spies caught here, all of whom have gone to prison, "because you are a member of the alleged establishment," Blunt answered, "I can't say."

Of his future he said "I hope to go back and do some work on art history."

Blunt returned later today to his London home after having secluded himself with friends over the weekend. After if he thought he would be allowed to live out his life here in peace, he shrugged his shoulders: "I hope so."