AUGUSTA — Maine’s two major political parties have raised a total of more than $1 million in recent months, and as November’s hotly contested elections near, the spending is just beginning, predicts one top political scientist.

The Maine Republican Party raised a total of about $576,000 from mid-July to the end of September, according to a political action committee report filed with the state on Tuesday. The Maine Democratic Party raised a total of $458,000 in the same period.

The Republicans have spent about $184,000 and the Democrats have spent about $218,000 over the last couple of months, according to their October quarterly PAC reports.

“This is going to go down as one of the most expensive, if not the most expensive, governor’s race in the history of Maine,” said Mark Brewer, a political science professor at the University of Maine.

Already, more than $1 million has been spent by groups hoping to influence the gubernatorial race in the general election cycle; that’s in addition to what the campaigns themselves have spent.

So-called independent expenditures are made by groups in “support of” or in “opposition to” candidates in the form of television, radio and print advertisements, as well as mailings. If spending by an outside group amounts to more than $100, it must be reported to the Maine Commission on Governmental Ethics and Election Practices.

Recent polls show Republican nominee Paul LePage virtually tied with Democrat Libby Mitchell, with independent candidates Eliot Cutler, Shawn Moody and Kevin Scott trailing. But about 25 percent of Maine’s likely voters are undecided.

“As long as the polls stay close, the money is just going to keep flowing in here,” Brewer said. “Independent expenditures here will go as high as those people who are interested in Libby Mitchell and Paul LePage winning deem that they have to go to give them the best chance to win.”

Spending in support of LePage’s campaign has outpaced that for Mitchell, $641,000 to $436,000, according to state filings. A new group, Campaign for Maine, spent $52,000 in support of Cutler.

Campaign for Maine spent the money on Oct. 7. It did not file its official independent expenditure report until Tuesday, though the reports are due within 48 hours.

Jon Doyle, an Augusta lawyer who is the PAC’s treasurer, said the filing error was inadvertent. Under Maine election law, the group could face a fine for the late filing.

The Republican Governors Association has spent about $400,000 and the Maine Republican Party has spent about $240,000, according to records.

On the Democratic side, a group called Citizens Who Support Maine’s Public Schools has spent about $216,000 and the Maine Conservation Voters Action Fund has spent about $210,000 to help elect Mitchell. Also, the Democratic Governors Association spent about $493,000 on advertising in Maine in September.

The state political parties, in addition to receiving help from outside groups like the Democratic Governors Association and the Republican Governors Association, each received large individual donations to help their candidates.

The Maine Democratic State Committee received $300,000 from S. Donald Sussman, a prominent donor to many Maine Democratic causes and the fiance of 1st District U.S. Rep. Chellie Pingree.

The Maine Republican Party received $200,000 from Ed and Marie Bosarge of Southport and $50,000 from Paul Coulombe of Cape Elizabeth.

The PAC supporting Cutler received $25,000 from Christopher Harte, former president of The Portland Press Herald/Maine Sunday Telegram.

Political action committees had until midnight on Tuesday to file their quarterly reports with the ethics commission.

Brewer said: “Mainers better buckle up, I think, and get ready for just a flood of television, radio and maybe even some print or mail advertisements over the next three weeks because it’s going to come fast and furious right up until Election Day.”

MaineToday Media State House Writer Rebekah Metzler can be contacted at 620-7016 or at: rmetzler@centralmaine.com