Gov. Larry Hogan (R) addresses the Maryland House of Delegates in Annapolis on Jan. 10, the first day of the state's 2018 legislative session. Standing behind Hogan is Lt. Gov. Boyd K. Rutherford (R). (Patrick Semansky/AP)

Gov. Larry Hogan released the first television advertisement of his reelection campaign Monday, part of a $1.3 million advertising blitz ahead of the gubernatorial primary that is costing substantially more than some of his leading Democratic opponents have in the bank.

With four weeks until the June 26 primary, Hogan and Lt. Gov. Boyd K. Rutherford have $9 million cash on hand and no Republican primary opponents. Their first television ad, which will air on broadcast and cable stations, highlights Hogan’s record on the economy and environmental issues, including efforts to improve the health of the Chesapeake Bay.

“Governor Hogan’s bipartisan leadership is creating real results for Maryland,” his campaign manager, Jim Barnett, said in a statement. “Under Gov. Hogan, Maryland is stronger than ever, and the comeback has only just begun.”

Democratic candidates Ben Jealous, Jim Shea, Rushern L. Baker III and state Sen. Richard S. Madaleno Jr. (Montgomery) also have launched television ads.

But they and the other Democrats vying for the nomination have a fraction of Hogan’s cash.

Jealous raised more than his rivals during the most recent campaign finance reporting period, pulling in $974,274 from mid-January to May. Baker and his running mate, Elizabeth Embry, who are backed by most of the state Democratic establishment, raised $542,867 in the same period.

But Jealous’s campaign spent $954,512 during the reporting period, most of it on staff salaries and media. He has $660,000 on hand.

The Democrat with the most cash to spend is Shea, a Baltimore lawyer. He and his running mate, Baltimore City Council member Brandon M. Scott, have $1.4 million available, according to the latest filings, after raising $671,674 during the reporting period.