Republican Larry Hogan raised more than $6.5 million over a recent three-month period, bringing his total contributions to roughly $10 million since he started campaigning for Maryland’s open U.S. Senate seat five months ago, his campaign told The Baltimore Sun on Friday.

The latest fundraising haul will be revealed in detail Monday, when candidates are required to submit their raising and spending figures for the second quarter of the year.

It will be the first campaign finance update since Hogan and Democrat Angela Alsobrooks won their respective primaries in May, setting up a high-stakes November matchup that could determine the control of the U.S. Senate and, as a result, is expected to attract large sums of outside money.

Hogan, a former two-term governor, has been a prolific fundraiser in his years as a public official.

In less than two months after he announced his latest campaign, he pulled in more than $3 million, including significant sums from national Republicans who urged him to enter the race.

The $6.5 million between April 1 and June 30 was similarly raised between three accounts. They are Hogan for Maryland, his primary committee; Hogan Victory Fund, a joint fundraising committee that can accept donations more than the regular $6,600 maximum; and Better Path Forward, a group he set up while exploring a 2024 presidential campaign.

“Our campaign is incredibly humbled by the support we’ve received across the state, raising more in a few months than our opponent raised in a year,” Hogan spokeswoman Blake Kernen said, referring to Alsobrooks’ fundraising during the Democratic primary. “Marylanders are fed up with politics as usual and are hungry for strong, independent leadership in Washington to put people over politics.”

Hogan has already been putting his money to use — running television ads reintroducing himself to voters and putting up billboards on the Eastern Shore, as well as traveling across the state.

Recent fundraisers have featured U.S. Sen John Thune, a South Dakotan who is looking to replace Mitch McConnell as the GOP’s Senate leader, and Georgia Gov. Brian Kemp.

His report Monday will indicate nearly $10 million raised in total through June 30, though that figure has been surpassed with additional contributions in recent weeks, according to Hogan’s campaign.

Alsobrooks, the Prince George’s County executive in her second term, has also seen the support of national figures in her party. She appeared twice with Vice President Kamala Harris during events in Prince George’s County in June, and political action committees with millions of dollars at their disposal have said they’ll assist her campaign this fall.