DES MOINES, Iowa — The chairman of a political action committee backing Arizona Republican Senate candidate Kelli Ward is assuming a senior role in her campaign, prompting questions about coordination between the groups, which is prohibited by federal law.

Veteran GOP strategist Ed Rollins, chairman and founder of Great America PAC, will remain head of the so-called super PAC, the group’s lawyer said Wednesday, as the campaign announced that Rollins was being named Ward’s campaign chairman.

Campaign finance law bars collaboration between a candidate’s campaign and super PACs such as Great America, which can solicit unlimited contributions to promote candidates, unlike federally regulated candidate committees.

Great America lawyer Dan Backer said Rollins will recuse himself from any PAC discussions of the Ward race. The group, affiliated with President Donald Trump’s former adviser Steve Bannon, also plans no further expenditures to promote Ward beyond the $20,000 it spent in August.