Sen. Charles W. Carrico (R-Grayson) during a floor session of the Virginia Senate at the state Capitol in Richmond on March 1. (Bob Brown/AP)

Gov. Terry McAuliffe, in a bid to save his embattled state Supreme Court pick, offered to support a coal tax credit if Southwest Virginia Republicans would switch sides in a long-running judicial battle, a state senator said Friday on the floor of the Senate.

McAuliffe (D) offered to extend the tax credit if senators from Virginia’s beleaguered coal country would help him return former justice Jane Marum Roush to the high court, said Sen. Charles W. Carrico (R-Grayson).

Carrico declined the offer. The Senate installed someone else on the court Thursday. And McAuliffe went on to veto what his office called “costly and ineffective coal tax credits.”

“It was nothing more than retaliation for not accepting his quid pro quo offer,” Carrico said. “I will not bend, I will not bow, will not break to his politically corrupt way to try to thwart the process of this General Assembly.”

Sen. Ben Chafin (R-Russell) also said that he met with McAuliffe, and that the governor made what he considered to have been a “threat” to veto the tax credit unless he bucked his party’s effort to install someone else to the seat.

Virginia Gov. Terry McAuliffe, right, reviews legislation with his staff in his office at the Virginia State Capitol on Friday. McAuliffe vetoed SB44, the coal tax credit bill. (Bob Brown/Richmond Times-Dispatch via AP)

McAuliffe said Sen. Minority Leader Richard Saslaw (D-Fairfax) pitched the idea of using the tax credit to try to peel off the senators from Southwest, which Saslaw confirmed.

Both Democrats defended linking the tax credit to the judicial tug-o-war, even as McAuliffe continued to blast the tax credit as a waste of taxpayer money in a news conference Friday night.

“Senator Saslaw called me yesterday ... and said he wanted to talk to several Southwest representatives, and said if they were willing to discuss the judge, would I be open to talking to them about the coal tax credit. I said, ‘Sure. That’s how we get things done. We compromise.’”

Saslaw criticized the Republicans for not taking a deal that might have benefitted their districts.

“Governor McAuliffe was not the first person to offer deals on stuff he liked or did not like, and he won’t be the last,” Saslaw said.

In a news release accompanying the veto, the governor’s office said that between 1988 and 2015, the state spent $610 million in tax credits to coal mine operators, electricity generators and other coal-related companies. Yet during that time, the number of Virginia coal miners fell from 11,106 to 2,946.

“It would be unwise to spend additional taxpayer dollars on a tax credit that has fallen so short of its intended effectiveness,” McAuliffe said in the statement.

McAuliffe’s willingness to wheel-and-deal on the coal tax could further complicate his relationship with environmentalists, who invested heavily in his 2013 campaign but have been disappointed with some of his stances as governor, including his support for off-shore drilling.

The episode is only the latest twist to the long, highly unpredictable Supreme Court saga.

Carrico and Chafin said Saslaw conveyed the offer Thursday, five minutes before a scheduled vote to install someone else on the bench. Since summer, McAuliffe has twice given the highly regarded former Fairfax County Circuit Court judge temporary appointments to the high court, but the legislature let them expire.

[Time runs out — again — for McAuliffe’s Supreme Court pick]

Republicans who control the legislature, irked that McAuliffe had not consulted them about appointing Roush and eager to assert their authority, planned to elevate Appeals Court Judge Rossie D. Alston Jr. instead.

That effort stalled for months, but was finally concluded Thursday with the election of Appeals Court Judge Stephen R. McCullough to the high court.