House Speaker Thomas P. (Tip) O'Neill Jr. (D-Mass.) sought yesterday to break the House-Senate deadlock over government funding of abortions or welfare clients.

O'Neill said he may use his power as Speaker to obtain a House vote perhaps today - on a relatively weak Senate-passed provision restricting use of federal funds for abortions.

The language is contained in the $60.1 million money bill for the Departments of Labor and Health, Education and Welfare. The House has voted a much tougher abortion-funding ban.

Senate Appropriations Committee leaders, headed by Warren G. [WORD ILLEGIBLE] (D-Wash.), have refused to go to conference on the abortion issue again until the House takes a vote on whether to accept the weaker Senate provision. The Senate has twice defeated the House provision, on votes of 59 to [WORD ILLEGIBLE] and 60 to 33, but the House has never voted directly on the Senate version. However, on Aug. 2 it voted 138 to 182 to re-endorse its own provision.

O'Neill didn't endorse the Senate provision, but he said he may call it up for a vote in the interest of getting the two sides back to conference so that work on the big money bill can be finished before the fiscal year ends on Sept. 30. O'Neill predicted the House will defeat the Senate provision, but a close vote could boost senators' bargaining power in conference.

Meanwhile, HEW and Labor officials said the dispute would have little, if any, immediate impact on grants to the states or Social Security and welfare benefits, even if final passage of the money bill is held up beyond the Oct. 1 start of the new fiscal year. October checks to welfare and Social Security recipients will go out this week as scheduled. However, the pay of about 150,000 employees of the two departments could be affected starting with checks due Oct. 18.

The federal government until recently had been performing about 250,000 abortions a year, financed by the government and the states under Medicaid, for low-income women.

However, last year Congress put into the Labor-HEW money bill a one-year ban on abortions funded by Medicaid except where needed to save a woman's life. The ban was blocked from going into effect by various lawsuits until Aug. 4, when the federal courts allowed it to become effective.

However, the ban expires Oct. 1 and the House is seeking to have it reenacted and continued for another year in the money bill. The Senate also has adopted a ban, but it is far weaker and allows federally funded abortions in a variety of cases, including where pregnancy resulted from rape or incest or where a doctor for whatever reason, considers it "medically necessary."