A sweeping court decision against the Texas prison system has been turned into an increasingly bitter political feud between Republican Gov. Bill Clements and Democratic Attorney General Mark White, foreshadowing a potential contest between the two in the 1982 gubernatorial race here.

Clements suggested last week that White had caved in to federal officials in handling the prisons case and said he was considering hiring "expert" counsel outside the government to carry on the state's appeal. White said the governor didn't know what he was talking about, either on the prisons case or the constitutionality of getting outside counsel.

Asked if he thought Clements was worried about him as a potential rival in 1982, the attorney general replied, "I would hope that would be the reason. The other [reason] is that he just doesn't understand" the issues in the prisons case.

The two men, both elected in 1978, have been sparring for some time over White's handling of various legal issues affecting the state, including bilingual education and school desegregation.

Over a month ago, Clements angrily protested White's decision to head off a federal citation against the Texas higher education system by agreeing to a series of steps to dismantle the remnants of segregation. Clements preferred confrontation with the federal government and angrily told White in private that the attorney general was exceeding his authority. In that case, White forced the governor to back down.

The Texas prisons case, a volatile political issue here, isn't likely to be settled so neatly. In December, after a long and contentious trial, U.S. District Court Judge William Wayne Justice issued a scathing ruling against the Texas prison system and ordered state officials to come up with a plan to end overcrowding, reduce violence against prisoners and improve medical care.

With both population and crime booming, Texas prisons are greatly overcrowded -- unconstitutionally so, Judge Justice declared. Many inmates are forced to sleep on the floor, and brutality among prisoners is commonplace.

Two years ago, Clements vetoed a $30 million prison construction program, but two weeks ago he announced a $35 million crash program to build new facilities. White said if Clements hadn't vetoed the funds two years ago, the new appropriation wouldn't be necessary -- and the state's defense in the prisons case would have been substantially stronger.

The attorney general made the comments as he announced the signing of a consent decree on parts of the prisons case. In it, the state agreed, among other things, to upgrade medical care for prisoners substantially. The state plans to appeal other parts of Justice's order, including the requirement of one prisoner per cell.

Later, Clements, stung by White's criticism of the veto, lashed out at the attorney general for not consulting him or prison officials and said White had agreed to some things the state had resisted in 1972, when the case began.

The governor "doesn't even know what it is he's agreed to, other than what he's read in the paper," Jon Ford, Clements' press secretary, said. "What has especially angered the governor is that White says the veto in some way jeopardized this case. It did not, and the governor has repeatedly told Mark White that he vetoed it on assurance of the prisons board and director of the Department of Corrections that that money would not in any way jeopardize their building program because it was funds that couldn't have been spent during that biennium. Anyway, White's the guy who handled the case and lost it."