WASHINGTON – A weekend government shutdown that neither party wanted was averted when Congress approved a compromise spending bill Thursday, as leaders overcame major defections by Republicans angry over what they considered excessive spending. To the dismay of liberals, the measure also blocks Obama administration plans to impose stricter nutrition standards on school lunches.

The Senate sent the measure to President Obama on a 70-30 vote, shortly after the House consented to the bill 298-121.

Though passage was by comfortable margins, the vote in both chambers highlighted GOP fissures over federal spending. House Republicans backed the legislation by just 133-101, while GOP senators voted heavily against the bipartisan bill, 30-17.

Many conservatives also were unhappy that the bill potentially would leave taxpayers on the hook for even more spending because it would expand the size of mortgages that could be insured by the Federal Housing Administration in wealthy areas from $625,500 to $729,750.

“Some say, ‘Oh, the tea party, you shouldn’t listen to them, they were angry people,’” Sen. Jeff Sessions, R-Ala., said. “Well, I think they were deeply frustrated people and, yes, somewhat angry. Why shouldn’t they be?”

The votes occurred against a backdrop of partisan gridlock among members of Congress’ supercommittee, which has less than a week to try agreeing to a debt-reduction plan.

Three high-profile Maine issues were addressed in the bill.

Among them, a provision co-authored by Sen. Susan Collins, R-Maine, keeping potatoes on the plate as part of the federal school lunch program.

Another provision co-authored by Collins allows trucks weighing up to 100,000 pounds back on all Maine’s interstates for the next 20 years.

And Amtrak funding in the bill will keep the Downeaster chugging down the tracks between Portland and Boston. Collins helped remove a deep cut to Amtrak’s budget backed by House Republicans.

Also backing the Amtrak funding was Sen. Olympia Snowe, R-Maine.

The potato battle centered on proposed restrictions on starchy vegetables in school lunches and breakfasts that threatened to drastically reduce the use of potatoes, which are a major crop in Maine.

Collins co-authored the truck weight provision with Democratic Sen. Pat Leahy of Vermont. It gives Maine and Vermont exemptions for heavier trucks to get off the side roads and back on all of Maine’s interstates. Currently, the heavier trucks can only use the Maine Turnpike. A number of states already have exemptions.

Democratic Reps. Chellie Pingree of the 1st District and Mike Michaud of the 2nd District also backed the potato and truck provisions and maintaining Downeaster funding.

The bill was the final approval for 2012 federal spending for several federal departments and agencies, including agriculture and transportation. It also keeps the rest of the federal government running through Dec. 16, since the 2012 fiscal year began Oct. 1, avoiding a government shutdown today.

MaineToday Media Washington Bureau Chief Jonathan Riskind contributed to this story.