Battle lines over extending the Voting Rights Act were drawn in the Senate yesterday as Sen. Jesse Helms (R-N.C.) threatened to filibuster "until the cows come home" and Sen. Donald W. Riegle Jr. (D-Mich.) said he would block action on other issues while conservatives stall on voting rights.

Sen. Ted Stevens (R-Alaska), acting as Senate Majority Leader while Howard H. Baker Jr. (R-Tenn.) is visiting China, said yesterday that the extension is now supported by 82 of the 100 senators as well as the Reagan administration.

But those who oppose the measure apparently plan to use all the procedural moves at their disposal to impede rapid passage. Stevens predicted that there will not even be a vote on the procedural "motion to proceed" to consideration of the bill until the middle of next week. Helms and his allies, including fellow North Carolina Republican John P. East, could then filibuster on the bill itself.

The bill under consideration is much like one passed 389 to 24 last October by the House.

The two major issues of contention are the standard of proof to be used to define voting discrimination and a current requirement in the law that nine states--including North Carolina--and parts of 13 others with past records of discrimination must obtain Justice Department approval before changing their election laws.

Helms said he wanted to "reach an understanding that the 40 counties in North Carolina will no longer be treated as second class citizens . . . they should no longer be required to clear with Big Brother in Washington every change."

Under a compromise worked out in the Senate Judiciary Committee, states or their subdivisions now covered would be able to "bail out" by showing they were in full compliance with the anti-discrimination provisions for the preceding 10 years.

The compromise, put together last month by Sens. Robert J. Dole (R-Kan.), Edward M. Kennedy (D-Mass.) and Charles McC. Mathias Jr. (R-Md.), would also make it easier for minority groups to prove violations by requiring them to show only that the changes in election laws or district boundaries had the effect, not the intent, of discriminating.

The Reagan administration had originally pushed for a standard that would require proof state or local officials intended for the discrimination to occur, but critics had argued the intent standard is almost impossible to satisfy, particularly in cases where officials responsible for election laws and boundaries may have been dead for many years.

The compromise would allow a judge to use a wide range of evidence--including a pattern of racially polarized voting, the makeup of voting districts, the numbers of minorities elected in relation to the local population, and a disparity in public services to minority neighborhoods--as factors in determining if voter discrimination has occurred.

The bill contains specific language making it clear that no judge should interpret the law to require any sort of proportional representation, a specter raised by the administration in months of hearings on the voting rights issue.

But in spite of that language, Sen. Orrin G. Hatch (R-Utah) raised not only the threat of mandatory proportional representation, but also predicted an avalanche of lawsuits that could overturn the electoral systems of cities all over the country.

In an oration that lasted nearly an hour, Hatch said the compromise measure "would move this nation in the direction of increasingly overt consciousness of race . . . The question of race will intrude constantly [with] racial gerrymandering and racial bloc voting."

Kennedy and Dole complained about the efforts by Helms and Hatch to delay the deliberations. Ironically, Hatch, who opposed the compromise, has been named by the Republican leadership to manage the legislation on the Senate floor, apparently because he headed the judiciary subcommittee that originally considered it.

But Kennedy predicted that the bill will pass in spite of efforts to amend and delay. "We may be briefly delayed by diehard efforts to cripple the act. But . . . once again, we shall overcome."