Cuba's parliament leader requested a special session Friday to amend the constitution to inscribe socialism as "untouchable" — a change called for by millions of Cuban during a signature campaign.

"I request that you convoke a special meeting of the National Assembly," Ricardo Alarcon said in a letter to President Fidel Castro. The missive was read Friday night during the government's nightly television program.

Alarcon previously had announced that lawmakers would meet in regular session on July 5.

But because of "historical transcendence" of the proposed constitutional amendment, "I have received practically unanimous support" for the idea from other lawmakers, Alarcon wrote.

The constitutional change was the subject of a campaign by the communist system's national support groups, which say they gathered 8.1 million signatures — more than 99 percent of the island's legal voters aged 16 and older.

Opposition leaders say the signature campaign was the government's response to a very different petition drive. The dissidents say they collected more than 11,000 signatures seeking a referendum asking voters if they favored reforms such as freedom of expression, the right to own a business and an amnesty for political prisoners.

Most Cubans first heard of effort, known as the Varela Project, last month in a speech by former U.S. President Jimmy Carter when he visited the island.

Organizers of Varela Project campaign delivered their petitions to the National Assembly on May 10 and have received no response.

Varela Project supports say that the official campaign to declare Cuban socialism "untouchable" is the government's response to their own drive to force a democratic opening in this still closed society.

The government, however, maintains it is protesting recent statements by President Bush who declared on May 20 that American travel and trade with the communist island would not be eased unless Cuba embraces democracy.