Gov. Harry Hughes, opting to do battle once again over one of the legislature's most volatile issues, will ask the General Assembly to make it easier for poor women to obtain state-funded abortions, State House sources said today.

Hughes has always been strongly "pro-choice" on abortion, but he was rebuffed when he undertook a similar effort in 1983, and chose not to pursue the issue last year. Now, his effort will be in the form of language in his fiscal 1986 budget.

The new budget drops a requirement that in cases other than rape, incest, or when the mother's health is in danger, a woman who wants to receive Medicaid funding for an abortion must get her doctor to certify in writing that there is "medical evidence" that her mental health would be seriously affected if she carried the baby to term.

The new language is identical to what passed the House of Delegates last year, according to sources. The Senate in 1984 rejected the House position, leaving intact the current requirement, which has been in force since 1980 and which pro-choice advocates say has greatly restricted the ability of poor women to obtain abortions at state expense.

The new language to be proposed by Hughes will allow doctors to perform abortions if they determine, "within a reasonable degree of medical certainty," that continuation of the pregnancy would have a "detrimental" effect on the woman's health.

Since the more restrictive language went into effect in 1980, the state has been paying for fewer than 3,500 abortions a year, compared to about 6,000 a year prior to its implementation.

Pro-choice advocates have argued that doctors became increasingly reluctant after 1980 to perform Medicaid abortions because of the requirement for written certification. In fiscal 1984, the state spent $1.7 million on Medicaid abortions, an average cost of $500 each.

It is unclear what effect the governor's decision to back the change again will have on the legislature. If the proposed liberalization passes the House, which will act first on the budget, it will set the stage for a potentially bruising battle in the Senate.

The Senate is generally considered to be pro-choice, but the majority is slim enough to make overriding a determined filibuster difficult.

Del. Timothy F. Maloney (D-Prince George's), a leading abortion foe, said he expects the legislature to make no change in the current language.

"The legislature has rejected attempts to both tighten up and liberalize the language, and I'd be surprised to find the General Assembly falling off the fence either way," he said.

The current Senate, elected in 1982, has never voted on the question of liberalizing abortion regulations, which has left some House members grumbling that they have taken all the political heat on the issue.

Last year, after the Senate budget committee removed the liberal language and refused to negotiate the issue in conference, Senate President Melvin A. Steinberg promised House members that he would propose legislation on the issue this year, removing the battle from the budget debate.

But under pressure from his committee chairmen, who warned Steinberg that any abortion statute would be lead to a statewide referendum, the Senate president reneged on his pledge.