A super PAC is violating campaign rules as it tries to help Republican Larry Hogan’s U.S. Senate candidacy, says a Montgomery County woman’s complaint to the Federal Election Commission.

The problem, according to the complaint filed by Danielle Veith of Kensington, is rooted in a button for donations that appears on the website of “Maryland’s Future,” a super PAC launched a week after the former two-term governor entered the race in February to succeed retiring Democratic Sen. Ben Cardin.

Clicking on the button allows people to donate not to the PAC, which has spent millions on pro-Hogan ads in the contest against Democrat Angela Alsobrooks, but rather to Hogan’s own campaign.

Super PACs can raise unlimited sums from corporations and others, the suit says, but they must remain independent of the campaigns they support. Formally known as “independent expenditure only” PACs, super PACS spend money on TV advertising and other campaign messaging, but they’re prohibited from coordinating with their favored candidates.

Veith’s complaint asks the FEC to investigate whether Maryland’s Future — seeded in March with $10 million from major Republican donor Kenneth Griffin — is violating FEC regulations barring super PACs from using their corporate funds “to facilitate contributions” to a candidate. If a violation is found, Hogan should refund contributions traceable to the super PAC, the complaint said.

Asked about the complaint, the Hogan campaign said in a written statement: “As a Super PAC, Maryland’s Future operates independently of our campaign in this and in all of its activities.”

Lance Trover, a spokesman for Maryland’s Future, said in his own statement that Alsobrooks, the Prince George’s County executive, “is the only candidate in this race who has broken FEC rules. Maryland’s Future is in full compliance with the law and abides by all the Federal Election Commission Regulations and guidelines. This is a frivolous complaint, and we are confident it will be dismissed.”

Trover’s statement referred to a June complaint against Alsobrooks by Virginia-based Americans for Public Trust. The group, whose leaders have been aligned with Republican causes, asked the FEC to investigate whether Alsobrooks improperly used funds from her state campaign account to assist in her bid for the U.S. Senate.

Alsobrooks’ campaign said that only its federal account was used to fund her Senate campaign, and called the Virginia group “Donald Trump-aligned.”

Myles Martin, an FEC spokesman, said Thursday that he could not discuss any open complaint because of confidentiality requirements.

Veith was unavailable to be interviewed, saying in a text message that her complaint would “speak for itself.”

With Senate majority control at stake in the Nov. 5 election, major Republican donors have stepped up to help Hogan, funneling $27 million to Maryland’s Future, according to its latest FEC report filed Tuesday.