Queen Elizabeth opened the new session of Parliament today with a speech spelling out the government's plans to introduce tough new law-and-order measures, cut taxes and continue its program of selling off state-owned enterprises while restricting public-sector spending.

The queen's speech, an annual event marking the beginning of the legislative year, was made to a joint session of the Houses of Lords and Commons. Traditionally, it is written by the prime minister, and simply read by the queen as a statement of the priorities of Her Majesty's Government.

Officials of government and opposition parties gathered respectfully this morning to listen to the sovereign's address and receive her blessing. But the afternoon brought a sharp parliamentary debate during which Prime Minister Margaret Thatcher's plans were labeled "vacuous," "mendacious" and designed to "divide and depress our economy and our society."

Labor Party opposition leader Neil Kinnock criticized Thatcher for failing to propose new measures to deal with unemployment, currently running above 13 percent, and accused her of turning the jobless into "defeated people."

The speech, and the first round of a week-long debate, outlined strategy for the two main political parties as Thatcher begins the second half of her second term in office and the country heads toward elections that must be held by spring of 1988.

Taking its cue from opinion surveys that indicate a majority of Britons are most concerned about unemployment and social services, the opposition attacked the government as uncaring and unfair.

Thatcher, however, said recent inner-city riots and a rising crime rate will increasingly focus public attention on law-and-order issues. Most opinion polls since early this year have shown her Conservative Party government slightly behind or on a par with the popularity of Labor and the third-party alliance of Social Democrats and Liberals. But in the past several weeks, the polls have begun to fluctuate slightly in the Conservatives' favor, something Thatcher's political advisers attribute to her tough stand against violence among soccer fans and a recent series of urban riots.

Among the 20 bills outlined in the speech, the government promised legislation that would require the organizers of public marches to give seven days notice to police, and give police comprehensive new powers to prevent those marches that they believe will cause disorder.

On the economy, Thatcher said she would continue to offer state-owned businesses and industry for sale and transfer into private hands, beginning next year with British Gas.