House Judiciary Committee Republicans are urging their Senate counterparts to probe Elena Kagan during her Supreme Court hearings next week over her role in crafting an Obama administration challenge to a 2007 Arizona law forcing employers to verify the immigration status of new hires.

The GOP lawmakers — led by House Judiciary ranking member Lamar Smith (Texas) — wrote Senate Judiciary ranking member Jeff Sessions (R-Ala.) on Thursday asking him and to question Kagan, who is solicitor general, about the “key role” that they claim she played in formulating an amicus brief that the administration submitted May 28 in support of a challenge to the Arizona law that is now pending before the Supreme Court.

The law allows Arizona to revoke the business licenses of companies that fail use the federal government’s E-Verify program to verify new workers’ immigration statuses.

The Republican Members contend that Kagan recommended the government argue in the amicus brief that the federal law pre-empts the Arizona law. The lawmakers cite an additional document — dated April 12 — that was submitted to the Senate Judiciary Committee as part of that panel’s review of Kagan’s legal and personal paper trail in advance of her confirmation hearings, which begin Monday.

“Though the final brief was submitted after Ms. Kagan had resigned her position as solicitor general and does not include her signature, it is clear that she ultimately approved the position taken by those who authored the brief,” the lawmakers wrote. “It is imperative that we know the extent of Ms. Kagan’s involvement in writing the brief, as well as the rationale behind her direct contravention of the letter of the law.”

The letter represents the latest in a series of questions by Republicans about Kagan’s record. GOP Senators have started referring to Kagan as a “political operative,” charging that she might let politics influence her judicial rulings.

“We are concerned that this is another instance in which Ms. Kagan’s legal reasoning took a back seat to her personal political philosophy,” Smith and his colleagues wrote.