VILNIUS, USSR — LITHUANIAN leaders are scrambling to come up with a plan to meet their republic's energy needs if Moscow makes good on its threat to cut off vital supplies. On April 17, Lithuania received the first word of cuts - a telegram from a Byelorussian natural gas supplier that Lithuania's share would be decreased immediately.
Hours later, Lithuanian Prime Minister Kazimiera Prunskiene told reporters she had been informed that the flow of crude oil to a large Lithuanian refinery would be cut completely. That refinery, in Mazeikiai, has reserves to continue production for one-and-a-half days, officials said.
If oil and gas cuts are put into effect, Lithuanian authorities say they will introduce rationing and seek help from individual Soviet republics and other countries. They acknowledge that if Moscow plans to throttle their economy, there isn't much they can do.
``If the world around us just stands by and watches this blockade, our situation will be bad,'' Lithuanian President Vytautas Landsbergis said. ``We'll need help from other countries to survive, to bring us fuel.''
That acknowledgment underlines the irony of Lithuania's bold break with the Soviet Union. The more independent it becomes of Soviet power, the more dependent it becomes on outside help.
``Our possibilities of storing materials are very limited, because we don't have the material resources to meet the demand of our industry,'' Lithuanian Vice President Kaziemir Motieka said. ``All our possibilities depend on imports. Our economists have discussed plans for this for many months.''
``But the only countermeasures we have in force right now are calmness, strong will, and reason,'' he added.
Lithuanians hope to barter
Lithuanian officials say they have been meeting for weeks with representatives of other Soviet republics, trying to arrange barter deals for fuel with republics such as Azerbaijan. Mrs. Prunskiene said that if fuel supplies are cut, she will pursue direct deals with factories and enterprises in the Soviet Union to sell Lithuania the goods it needs. She said that Lithuania has promises from some Soviet republics and individual factories to ship goods.
Lithuanian Foreign Minister Algrinas Saudragis traveled to Norway April 18 to discuss the planned economic sanctions, Prunskiene said. She said she would also seek immediate aid from Denmark and Finland.
``Now we are waiting for other republics to say they will not fulfill the obligations that Gorbachev mentioned in his letter, but rather will have direct economic relations with Lithuania,'' said Laima Andrikiene, an aide to Prunskiene and a parliament deputy.
But Lithuanian officials declined to release details of their discussions with other republics and countries, and no officials from other Soviet republics have publicly promised to route supplies to Lithuania. Prunskiene said she will send telegrams to factories in Lithuania and other republics that would be affected by any fuel cuts, urging them to pressure Moscow to rescind any economic sanctions.
By Tuesday night, Prunskiene said she had not yet contacted the leaders of the two other Baltic republics about the threatened cuts. She said the ``Baltic Community'' agreement for mutual economic assistance among Lithuania, Latvia, and Estonia, signed by the three states last week, does not include measures for the immediate supply of oil and gas to Lithuania.
In another irony, economic sanctions may wind up hurting most the people Soviet President Mikhail Gorbachev says he is defending - Lithuania's 17 percent minority population of Russians, Byelorussians, and Poles. They make up the majority of factory workers, and if Lithuania's energy supplies are slashed, factories will be hit first, Lithuanian officials say. Many workers fear losing their jobs.
Lithuanian leaders say they have been waiting for economic sanctions from Moscow since their March 11 declaration of independence. But despite this brave face, the threat of sanctions this week publicly divided the Baltic republic's legislature for the first time.
Some government officials suggested the republic backtrack on its consistently defiant stance toward Moscow. And at least one lawmaker proposed instituting a moratorium on putting any post-independence laws into effect.
``We should understand that the situation in the Soviet Union is very complicated. Russia and the Ukraine are virtually soaked in kerosene now. And God forbid we should set a burning match to that,'' said Kazimieras Antanavicius, a legislator and economist from Vilnius, in a speech in parliament. ``That could lead to catastrophe.''
Republic depends on imports
Lithuania, with few natural resources of its own, is dependent on raw materials it imports from elsewhere in the Soviet Union. While Lithuania produces few essential exports, the republic's leaders say, the Soviet Union possesses much that Lithuania cannot live without.
On the plus side, Lithuania produces 90 percent of its own meat and butter needs and 80 percent of its clothing requirements. It also holds a virtual monopoly in the Soviet Union on the production of some electronic goods, such as radio and television components, refrigerators, and certain electronic tools.