The author of the biggest U.S. restrictions to trade with the Soviet Union and Eastern Europe said today that those restrictions should be waived immediately but not repealed. ``The principles of Jackson-Vanik should be solidly retained ... as a back-up insurance that we will not abandon world leadership on the issue of human rights,'' former Rep. Charles A. Vanik, D-Ohio, told the House Ways and Means Committee. Vanik, however, disagreed with the Bush administration's insistence that Moscow make law its recently adopted free emigration policies before the United States lifts the high tariffs imposed on Soviet imports. President Bush promised Soviet President Mikhail S. Gorbachev at the Malta summit in December that if the emigration policies are made law, Bush would seek a one-year waiver of the Jackson-Vanik restrictions as part of a new U.S.-Soviet trade agreement the two leaders hope to sign in June. ``I judge the Soviet Union by the deed more than the statute,'' Vanik said of recent Soviet emigration policies. ``The process appears to be a well-established, non-reversible course.'' He said U.S. slowness in normalizing trade relations with Moscow and the newly reincarnated governments of Eastern Europe risks losing those fledgling free markets to other Western powers such as Japan, West Germany and Italy. House Democrats expressed frustration that the administration has not moved faster to lower the barriers to expanded trade with countries behind the crumbling Iron Curtain _ a region one businessman described as the biggest new market since the opening of the Americas in the 18th and 19th centuries. ``We're worried, we don't see any actual planning for this,'' said Rep. Sam Gibbons, D-Fla. ``We don't spot the administration doing a lot.'' Business people have favored outright repeal of Jackson-Vanik, saying they are unwilling to make the type of investments Bush has called for to rebuild the economies of the Soviet Union and Eastern Europe without better assurance that policies will not be changed suddenly. ``If you think we're going to make investments on the basis of an 18-month waiver, we're not,'' said John Murphy, chairman of Dresser Industries in Dallas. Vanik, however, predicted that repeal of the 1974 law that he co-wrote with the late Sen. Henry Jackson, D-Wash., would have ``a tough time in Congress'' because of 45 years of Cold War conditioning to distrust the Soviet Union. ``It's a matter of political reality,'' he said. ``I think the rest of America is not yet prepared to consider anything more for the Soviet Union than a waiver.'' The law was enacted largely to stop the last proposed U.S.-Soviet trade agreement initiated by former President Nixon in 1972 and to pressure Moscow to remove restrictions that prevented Soviet Jews from emigrating to non-communist countries. Basically, it prohibits all export credits or credit guarantees to Soviet bloc countries that restrict emigration. The law also subjects Soviet bloc exports to the United States to stiffer tariffs than those applied to other countries. Soviet emigration has climbed from just under 2,000 in 1986 to approximately 195,000 in 1989. American officials acknowledge the biggest barrier now is limits the United States and other countries are putting on the number of Soviet immigrants they will accept. ``The reasons for Jackson-Vanik no longer exist, but people find a reason to keep it alive,'' said Rep. Thomas J. Downey, D-N.Y. Meanwhile, Senate Democrats on Tuesday proposed a new half-billion dollar aid package _ $200 million more than Bush wants _ to foster emerging democracies in Eastern Europe. The bill, introduced by Sen. Claiborne Pell, R-R.I., chairman of the Senate Foreign Relations Committee, would augment $738 million in aid already approved for Poland and Hungary with $511 million targeted for Czechoslovakia, East Germany, Romania, Bulgaria and Yugoslavia. Pell said he would not be surprised if his proposal is increased during the legislative process ``in view of the profound interest of the United States in supporting positive developments in Eastern Europe.'' Bush, as part of the fiscal 1991 budget he proposed Monday, asked for $300 million as a ``special assistance initiative'' for Soviet bloc nations, including Poland and Hungary.