AUGUSTA — Maine television viewers should brace for a blitz of last-minute political commercials, mainly on the controversial Maine Turnpike referendum, before Tuesday’s election.

According to campaign-finance reports filed with the state ethics commission Wednesday, the Vote No on #1 Coalition, the group that favors widening the Maine Turnpike, had raised almost $1 million through last week.

The Campaign for Sensible Transportation, the group trying to block the turnpike widening, had raised about one-fourth as much.

Both sides were spending heavily on TV commercials, for production and air time.

Campaign efforts also are under way for two other questions — bond issues to promote job creation and to buy more public lands.

The Vote No on #1 Coalition, heavily supported by large businesses, was outspending the Campaign for Sensible Transportation 5-to-1.

The Vote No group reported raising $980,767 and spending $995,454 to defeat the referendum, leaving a net debt of $14,686.

The coalition reported spending $115,000 to buy air time and space for political advertising during the reporting period of Oct. 1-24.

Wal-Mart Stores Inc. was by far the biggest contributor to the Vote No on #1 Coalition, donating $50,000. Other major contributors were Georgia-Pacific Corp., $15,000; F.R. LePage Bakery of Auburn, $10,000; Maine Motor Transport Association, $10,000; Boise Cascade Paper Group, $8,000; and Fraser Paper Ltd. of Madawaska, $7,500.

There are no limits on how much an individual or business can give to a political-action committee.

The Campaign for Sensible Transportation had raised $226,768 and spent $186,477. The group had a cash balance of $40,291 and debts of $40,703.

The group spent $47,000 with Shafto & Barton of Houston, Texas, to buy advertising air time and space. The group spent $11,200 with Joe Slade White Communications Inc. of New York for production of advertising.

The biggest contributors to the Campaign for Sensible Transportation during the reporting period were Richard Cashin of New York, Leon Gorman of Yarmouth, Henry Harris of Pennsylvania, Harvey Picker of Camden, and Dan Wellehan of Westbrook, all of whom gave $5,000.

Several smaller campaigns also are under way.

A group called Jobs for Maine’s Future was campaigning for passage of question No. 4, a $7.5 million bond issue to provide financial help to Maine businesses.

The group raised $17,160 and spent $16,900, all on advertising.

The Nature Conservancy Action Fund was campaigning for passage of question No. 5, a $5 million bond issue for public-lands acquisition.

The group raised $52,626 and spent $42,522 — all on printing and direct mail. The Nature Conservancy Action Fund in Arlington, Va., gave $50,000 to the campaign.

Another group called Citizens to Save Maine’s Heritage raised $6,117 and spent $2,500 campaigning for passage of question No. 5.