Jewish activists organized protests in several major Soviet cities today to dramatize their thwarted emigration requests on the opening day of the troubled Madrid conference.

Jewish sources said the actions, by more than 200 Jews who have been refused permission to leave the Soviet Union, included announcement of three-day fasts by 190 persons and a petition to the figurehead Soviet legislature protesting that the state "has failed to honor commitments it assumed for free emigration."

More than 100 "refusedniks" entered the building of the Supreme Soviet legislature this morning to submit the petition, in the form of a letter signed by 268 Jews from Moscow, Leningrad and elsewhere.

The letter asserted that "our countless appeals and applications are simply ignored. Even brothers and sisters are not treated as immediate relations. Many of us haven't been able to get any response to requests. Very often the reason for rejection is not cited."

Jewish emigration peaked last year at more than 50,000, but so far this year has been averaging about 2,500 a month. The number of refusals has climbed, with the authorities insisting that only close relatives have the right to leave under the provisions of the 1975 Helsinki agreement on European security, which incorporated several articles regarding human rights.

Activists said the protesters include 139 in Moscow, 10 in Kharkov, 2 in Tbilisi, 15 in Kiev, 7 in Kishinev and 27 in Riga.

"It is the widest demonstration in 10 years," Jewish activist Viktor Brailovsky said at a press conference. "We can't control the Madrid conference, but this is all we can do."