House Speaker Thomas P. (Tip) O'Neill Jr. (D-Mass.), declaring that Reaganomics is "pie-in-the-sky optimism," called on congressional Democrats yesterday to enact legislation as soon as possible to "get this country working again."

In a "Dear Democratic Colleague" letter also signed by Majority Leader James C. Wright Jr. (Tex.) and Majority Whip Thomas S. Foley (Wash.), O'Neill said that when Congress returns to work Nov. 29 its top priorities should be to pass bills it tried to pass earlier this year to create 400,000 jobs in the housing and construction industries.

"Congress passed legislation in June subsidizing moderate-price housing and creating some 200,000 jobs. The bill was vetoed. We need to try again," O'Neill wrote.

"The House passed legislation in September putting 200,000 people to work rebuilding our nation's bridges, roads, water systems and public facilities. Faced with administration opposition, the measure was defeated in the Senate. We need to try again," he added.

Saying President Reagan's view of the country's economic outlook is "at odds with the real-life data" of unemployment, O'Neill said Congress must act on its own to "create jobs and put Americans to work."

Declared O'Neill: "When we return to work Nov. 29, we must give top legislative priority to job creation and economic recovery." O'Neill said that "at minimum," laws must be passed to create jobs in the housing and construction industries.

He also said that at the urging of the Democratic leadership of both chambers, Joint Economic Committee Chairman Rep. Henry S. Reuss (D-Wis.) is holding emergency hearings during the current recess to hear testimony from economists on what can be done to reduce unemployment.

The next session is scheduled Wednesday.

"With the aid of this testimony," O'Neill said, "he will develop suggestions for additional steps we should take during the lame-duck session.

"President Reagan's televised remarks last Wednesday make it clear that he disagrees with this Democratic agenda," O'Neill went on.

"We believe that the results of the Nov. 2 election will make it clear that the American people vastly prefer a back-to-work program to the president's 'stay-the-course' philosophy.

"In making their preference known, the American people will send a clear-cut message to the White House: get this country working again."