Virginia Gov. John. N. Dalton ordered an end yesterday to state payment for elective abortions for poor women, a decision that his medical assistance advisory committee has called an act of "blatant discrimination" that will revive "the horrible era of back-alley abortions."

Dalton's action reverses a decision announced by former Gov. Mills E. Godwin on Jan. 11, three days before he left office. Godwin told the General Assembly then that he had "deliberately" taken no action to change Virginia's present policy of paying for elective abortions for Medicaid patients so that the Assembly itself could debate the issue.

Dalton's brief written statement announcing the policy change said it would insure that the abortion issue is "fully joined for consideration by the General Assembly."

However, Dr. William Grossman, chairman of the Governor's Advisory Committee on Medicare-Medicaid, said in an interview that he considers the Dalton action unnecessary. "If he wants to leave it to the Assembly," he didn't have to do anything."

It has been expected that bills permitting and prohibiting state payment for elective abortions would be introduced in this Assembly session, but the Dalton action clearly shifts the legislative burden to proponents of abortion aid for indigent patients.

If the Assembly simply takes no action on the issue, then Medicaid patients will no longer be able to receive state aid for abortions that are not needed to save the life of a pregnant woman.

Dalton's action was precipitated by a Nov. 30 recommendation by the state Board of Health to limit abortion aid to those cases in which doctors determine that childbirth would endanger the life of the woman. The board does not have the power to change Medicaid benefits without the approval of the governor.

The 4-to-1 vote, with three members absent, overruled recommendations of the state health department staff and the Medicaid advisory committee. Dr. Grossman said the 16-member advistory committee considered the issue on two separate occasions and voted unanimously both times to leave the abortion aid policy unchanged.

Federal funds for elective abortions were cut off last August, but Virginia has until now picked up the federal share of abortion benefits for Medicaid patients. The cost of about 4,000 abortions for these patients in the last fiscal year was about $450,000. This is about 0.02 percent of the entire state Medicaid bill of $250 million.

Proponents of continued Medicaid payments for elective abortions have argued that their cost is far less than the health and welfare costs that will result from denial of abortion aid.

Dr. Grossman said the Medicaid policy chnge will have no impact on the number of abortions, which he said "have been declared by the highest court in the land to be a matter of choice for the individual woman." He said the committee advised Godwin in writing that to deny abortion aid to medically indigent patients would be "blatant discrimination."

When the possibility of an abortion aid cutoff was raised during the gubernatorial campaign last September, Dalton said only that he considered abortions to be "a matter between a lady and her doctor."

His statement yesterday said that the decision of the Board of Health "is in accord with my own personal feelings, although I would have preferred that cases of rape or incest be included" in the cases covered by Medicaid benefits.

When asked why the governor approved a benefit plan that does not cover such cases, Dalton spokesman William A. Royall said the governor is leaving those issues to the Assembly.

Dr. Grossman said Dalton did not consult him before announcing his decision. Royall said the governor's secretary of human resources, Dr. Jean L. Harris, briefed him on staff and committee recommendations before the decision was made.