Iowa Republicans have proposed new restrictions on the state's Democratic attorney general to prevent him from joining lawsuits that target President Donald Trump's administration.

Tom Miller, as the state's chief legal officer, joined six lawsuits in 2018 that were initiated in other states seeking to block many of Trump's policies, including separating families on the southern U.S. border and requiring citizenship information in the 2020 census.

Miller’s office also has joined other states in signing on to about 26 amicus briefs and 50 letters to federal agencies challenging the Trump administration's actions, according to the attorney general’s office. The office estimates its cost of participating falls between $7,500 and $10,000.

TOM MILLER OP-ED: Lawmakers should not handcuff attorney general's office

But Republicans say the efforts are partisan.

"We have a Republican governor, we have a Republican Legislature, and we have had an attorney general that has been going outside of the state taking part in lawsuits that are the complete antithesis to the agenda that the governor and the Legislature has set," said Rep. Gary Worthan, R-Storm Lake.

Lynn Hicks, a spokesman for Miller’s office, said he was unaware of any lawsuits the office joined in targeting the actions of Democratic President Barack Obama’s administration.

Worthan filed his proposal this week, tacking it onto a budget bill moving through the Iowa House of Representatives, that would require Miller's office to get permission to join out-of-state lawsuits. If the proposal becomes law, the attorney general could only prosecute non-Iowa suits if requested by the governor, the General Assembly or the Executive Council, which also includes the governor.

On Thursday night, Republican lawmakers on a key House budget committee approved the provision, signaling it has some support.

"What’s being proposed sort of goes to the heart of the office of the attorney general," Miller told the Des Moines Register. "Deciding when to file a lawsuit and whether there’s a legal basis for it, is within our authority, expertise … what the public expects of us."

In addition to joining multistate lawsuits targeting the Trump administration, Miller’s office also has participated in multistate litigation related to consumer protection in industries such as for-profit colleges and universities, mortgage and credit card abuses and debt collection.

In December 2018, for example, Iowa was the lead state in a lawsuit against Wells Fargo that resulted in a $575 million settlement, including a $6.2 million payment to Iowa’s Consumer Education and Litigation Fund.

"We believe Iowa would be the only state in the nation to have these restrictions on the power and duties of the Attorney General," Miller said in a later statement Thursday afternoon. "As written, the language would affect far more than lawsuits against the federal government and would limit our ability to act on such issues as consumer protection, antitrust violations and Medicaid fraud."

Miller, who is the longest-serving sitting state attorney general in the country, noted that a legislative effort in Wisconsin to restrict that AG's powers is tangled in a lawsuit.

There, outgoing Republican lawmakers passed legislation preventing the incoming Democratic attorney general from withdrawing Wisconsin from a multistate lawsuit against the Affordable Care Act.

If Iowa’s proposal becomes law, Miller did not dismiss the possibility of a lawsuit.

This isn't the first time Worthan has openly criticized Miller's office. Last year, the Republican lawmaker called out lawsuits and other legal actions taken by the attorney general's office during a House floor debate on Miller's office budget. He threatened to dock the office’s budget by 10 percent in response to its involvement in these lawsuits.

Worthan cited several legal actions from Miller's office, including on the census case and suits against the 2017 travel ban.

“If he had had to come to us for any of those, he wouldn’t have gotten approval to take part,” Worthan said. “It’s up to the governor and the Legislature to set the agenda for the state, not the attorney general. And that’s the motivation behind it.”

Pressed on whether Worthan’s proposal is linked to how Miller has participated in lawsuits tied to the Trump administration, Worthan claimed Miller has joined more lawsuits during the Trump administration than the Obama administration.

“Is he using his office as a political cudgel?” Worthan asked of Miller. “That’s kind of what we’re getting at.”

It's unclear whether Worthan's proposal will advance out of the Republican-controlled chambers. Sen. Julian Garrett, R-Indianola, who helps develop justice-related funding out of the Senate, said he's still reviewing the proposal.

​​​​​​​Register reporter Brianne Pfannenstiel contributed to this report