Terry McAuliffe has expanded his fundraising lead over Ken Cuccinelli II in the closing months of the Virginia governor’s race, raising more cash than any past contender for the commonwealth’s top office.

McAuliffe (D) raised $6.2 million in September and had $1.85 million in the bank as of Sept. 30, according to reports filed Tuesday. The haul was by far his best to date for a single month, and his continued cash prowess has allowed him to get ahead of Cuccinelli (R) in the advertising wars. Several recent polls have shown McAuliffe leading in the contest.

Overall, according to the nonpartisan Virginia Public Access Project, McAuliffe raised $24.7 million through the end of September, more than $10 million above what Gov. Robert F. McDonnell (R) — a widely respected fundraiser — had taken in at the same point in the 2009 race.

Cuccinelli, the state attorney general, reported raising $3.4 million in September and had $1 million on hand at the end of the month.

“Heading into the final days of the election Virginians continue to provide Terry McAuliffe’s campaign with overwhelming support, helping him to communicate his message of mainstream solutions to grow and diversify the economy,” said McAuliffe spokesman Josh Schwerin.

Cuccinelli spokeswoman Anna Nix said the Republican’s showing was evidence that he “continues to build grass-roots support” for his bid.

“Today’s finance report shows that we have the resources necessary to defeat an opponent who is famous for one thing: raising money,” Nix said.

Robert Sarvis, the Libertarian candidate for governor who has been polling better than third-party candidates usually do, raised $27,000 in September and had $22,000 in the bank.

In the lieutenant governor’s race, state Sen. Ralph Northam (D-Norfolk) raised $433,000, compared with $263,000 for Chesapeake minister E.W. Jackson.

State Sen. Mark R. Herring (Loudoun), the Democratic nominee for attorney general, raised $1.1 million in September — more than double what he raised in July and August combined — and had $1.4 million in the bank at the end of the month.

Herring’s GOP opponent, state Sen. Mark D. Obenshain (Harrisonburg), reported raising $564,000 in the month and had $320,000 on hand. The Republican State Leadership Committee reported giving Obenshain $500,000 on Oct. 10, which will help balance the scales in that race.

Atop the ballot, McAuliffe’s financial advantage has given him a sizable edge on the airwaves.

In the past month, McAuliffe’s campaign has outspent Cuccinelli’s on television advertising $3.9 million to $2.9 million, according to data from the ad-tracking firm Kantar Media. Groups supporting McAuliffe have spent an additional $1 million, while Cuccinelli allies have kicked in $622,000.

The battle has grown more lopsided in recent days. From Oct. 7 to 13, McAuliffe and his backers spent $1.1 million to the pro-Cuccinelli side’s $477,000.

Outside of the two campaigns, the most active advertiser in the past month has been NextGen Climate Action Committee, the super PAC created by San Francisco hedge fund billionaire Tom Steyer. The group has spent more than $500,000 on ads attacking Cuccinelli’s ethics and environmental stances. The National Education Association has weighed in for McAuliffe with nearly $300,000.

On the Republican side, two super PACs — the Virginia Principles Fund and the Ending Spending Action Fund — have made six-figure buys, while the National Rifle Association has shelled out close to $100,000.

The Republican Governors Association, a heavy advertiser over the summer, has largely left the battle of the airwaves to the Cuccinelli campaign but hasn’t stopped helping the GOP nominee. It gave Cuccinelli $500,000 on Oct. 10 and has made $7.9 million worth of cash and in-kind donations overall, according to the Virginia Public Access Project.

The RGA’s largess has helped balance a much smaller effort by the Republican National Committee, which has given to the Virginia GOP this cycle only a fraction of what it gave in the 2009 election.

The Democratic Governors Association has spent or donated just under $5 million for McAuliffe.