Virginia officials are once again on a collision course with Republican Gov. John N. Dalton over state Medicaid funding for abortions, but this time his opponents are predicting they will prevail.

The House health committee, long considered one of the General Assembly's most liberal panels, voted today by a margin of more than two to one to allow Medicaid funding of abortions in cases of rape, incest or gross fetal abnormatilty. Dalton last year vetoed state regulations that would have allowed poor women to use state funds for abortions under those circumstances and has hinted he will do the same this year if the legislature mandates the funding.

Despite Dalton's warning that he would block anything that could add to the Medicaid program's $68 million budget deficit, proponents of the abortion measures said today they are prepared to override any veto.

"We're going to come back to take care of those vetoes this year," said Del. Frank Slayton (D-Halifax), noting that the General Assembly will hold its first veto-override session this spring. "We're telling the governor that we care more for poor people than he apparently does."

The health committee decision marked the second political setback this week for Dalton, whose power appears to be waning as his four-year governship draws to a close. A few days ago, members of another House panel approved legislation that would lift half of the state's sales tax on food -- a ; measure that Dalton has strongly opposed.

A Dalton aide declined today to discuss the governor's position on the abortion-funding legislation. "We have a policy not to comment on these things as they go along," said Charles J. Davis III.

The question of abortion is always a stormy one in Richmond, where antiabortion groups and representatives of the Catholic Church last week used an emotional hearing to charge that approval of the legislation would amount to a return to the moral degeneration of Nazi Germany.Others brought graphic stories about the suffering of mothers of deformed children or those who were forced by rape or incest to carry children they do not want, arguing that the bill would extend to these women a constitutionally guaranteed choice of aboriton that is available to women who can afford to pay for the operation.

According to J. Samuel Glasscock (D-Suffolk), sponsor of the bill, the legislation would affect only about 45 people a year and would cost of about $20,000 annually. Proponents of the legislation have maintained that the price tag is far lower than the cost the state would bear in caring for unwanted and incapacitated children.

The State Board of Health issued regulations last fall to provide Medicaid funds for aboritons in cases of rape or incest but Dalton vetoed them, citing both "money and morality." Opponents say they have all but abandoned hope of challenging the rape and incest funding in the House and Senate, where full Medicaid funding for abortions failed by only one vote several years ago. The opponents are hopeful that abortion funding in cases of fetal abnormalities will be rejected because it will be difficult to enforce.

"Heck, by the time it's all over, a doctor could just write these things out like a prescription for an aspirin," said Del. David G. Brickley (D-Prince William), who voted against the legislation.

Under current regulations, Virginia funds Medicaid abortions in cases in which the pregnancy seriously endangers the mother's life. According to representatives of the Virginia Organization to Keep Abortion Legal, that definition has not been interpreted to included cases of rape, incest and fetal abormality.