MERRIFIELD, Va. (AP) _ They were told not to come, but they did anyway - immigrants with ''lots of dreams'' lining up near a Washington-area post office, hoping their applications for residence visas will be among the 40,000 the State Department will accept beginning at 12:01 a.m. Monday.

Tac Shibata has been here a week, first in line at the only post office designated to receive an expected 5 million ''green card'' applications.

But the Japanese student's application may not be among the first 40,000 the government will accept from eligible foreigners.

''We've tried to tell them,'' a State Department official said Thursday. ''But no matter how many times you tell them, they're going to believe that being in line is going to be the best way.''

Shibata, 27, drove from New York City with two friends and arrived Oct. 3.

''Everybody has lots of dreams.'' said Shibata, who is taking English lessons at night and wants to enroll fulltime. ''American people think Japanese are rich. We are poor,'' he said, pointing at his friends.

As of Thursday, about 30 people had set up camp at a gas station next to the post office. The State Department expects thousands to mass outside the office by Monday morning, but it doesn't recommend lining up: the post office will not process mail delivered in person until noon Monday - 12 hours after it begins processing applications delivered by mail. Mailed applications received before midnight will be rejected.

''Mail coming from wherever - say Los Angeles, mailed on Thursday - may or may not have a better chance of getting delivered to the (State Department),'' said the official, who spoke on condition of anonymity.

The official said the department tried to discourage queuing up to give those living abroad an equal chance for the green cards, which allow foreigners to live and work in the United States.

The 1990 law that authorized the special green card program gives the Irish a better chance; it requires that 40 percent - or 16,000 of the permanent residence visas - go to Irish living abroad or in the United States.

Although the Irish post office is on strike, Irish postal workers on Wednesday took green card applications and made sure they were on flights to the United States on Thursday, according to U.S. Postal Service spokesman Bob Hooving.

Some fear authorities won't be able to handle the post office crowds.

''People are very, very serious,'' said Kazumi Sakao, who came here to assist Shibata. ''It spells trouble. There is no trouble with 140 people in line, but in two days, it's going to be big trouble.''

Walter Baryla, a native of Poland, drove to the area from Chicago with four friends.

''We are confused because we think the State Department changed the rules, but we are not sure,'' Baryla said. ''A Polish journalist came here and said rules may have changed.''

He said postal authorities should take charge of the situation.

However the post office said it has nothing to do with the immigrants waiting in line.