A federal court announced Wednesday it will go through with plans to hire an outside expert to redraw several North Carolina legislative districts, rejecting arguments by Republican lawmakers that they should get another crack at fixing House and Senate boundaries.

An order from the three-judge panel appointed a Stanford University law professor to redo by Dec. 1 two Senate and seven House districts that the judges previously ruled were among 28 districts from six years ago tainted by racial bias.

The GOP-dominated legislature approved new maps in August based on rules that prohibited the use of the racial data of voters in forming them. The judges said those new boundaries didn’t fix all of the problems. In the order, they questioned whether the GOP’s use of political data and protecting incumbents in favorable boundaries “embedded, incorporated and perpetuated the impermissible use of race that rendered unconstitutional the 2011 districts.”

A lawyer for the Republican legislative leaders wrote the Greensboro federal court on Monday that bringing in Nathaniel Persily as a special master would be premature and questioned his impartiality. But the panel disagreed.

“The state is not entitled to multiple opportunities to remedy its unconstitutional districts,” the order reads, adding the legislators’ objections to Persily “are speculative and insubstantial.”

The judges told Persily he can review voter racial data while doing his work to ensure unconstitutional racial gerrymanders are cured but can’t use election results. The judges plan to review his work in a court hearing in January before deciding whether to accept his proposed boundaries. Candidate filing begins in February.

“Constitutionally adequate districts must be in place in time for the 2018 election, and the court finds it appropriate to appoint a special master to assist the court in drawing such districts, should the court ultimately determine they are necessary,” the order says.

Amy Auth, a spokeswoman for chairmen of the House and Senate redistricting committees, said late Wednesday the court has quickly seized the constitutional and sovereign right to draw districts from lawmakers to an “unelected California college professor with clear conflicts of interest. We are disturbed the court has apparently planned all along to achieve its preferred political outcome and are reviewing our legal options.”

The three-judge panel is comprised of U.S. Circuit Judge Jim Wynn and District Judges Catherine Eagles and Thomas Schroeder. President Barack Obama nominated Wynn and Eagles. President George W. Bush nominated Schroeder.

A lawyer for voters who successfully sued over the 2011 maps was pleased with the order.

“We think it’s certainly helpful to have a special master at this stage,” Allison Riggs with the Southern Coalition for Social Justice said in an interview, adding it “keeps all doors open to having finally constitutional districts for our 2018 elections.”

The 2011 House districts that Persily is directed to redraw include three in Mecklenburg County, two in Wake County, one in Guilford County and one covering parts of Sampson, Duplin and Wayne counties. One Senate district is in Guilford and the other is in parts of Hoke and Cumberland counties.

Districts adjoining the targeted districts also will have to be adjusted. The order also directs Persily to shy away from drawing any districts that don’t have to be, in keeping with a restriction in the state constitution.

The 2011 maps helped Republicans expand and retain veto-proof majorities in the General Assembly, making it easier for them to push through a conservative-leaning agenda.