Foes of ballot measures that would cut North Dakota's income tax and establish a savings account for oil tax collections have donated almost $556,000 to defeat them, campaign disclosure reports show.

Most of the money has come from state and national organizations that represent teachers and government workers. The AARP, an advocacy group for the elderly, has donated $50,000 to the campaign, disclosure reports say.

They are opposed to Measure 1, which would establish a new trust fund for surplus oil taxes in North Dakota's Constitution, and Measure 2, which would cut North Dakota's individual income tax rates roughly in half. Corporate tax rates would be trimmed by 15 percent.

Critics of the measures say their approval could jeopardize efforts in the Legislature to relieve pressure on local property taxes. The proposed oil tax trust fund would set aside too much money and make it too difficult for the Legislature to access the fund, they say.

"We have no friends in these fights, usually. We are the only ones who stand between students and educators and a lot of bad things," said Greg Burns, director of the North Dakota Education Association.

Duane Sand, the chairman of the initiative campaign on behalf of Measure 2, and state Rep. Dave Weiler, R-Bismarck, who sponsored Measure 1 in the 2007 Legislature, said they were astonished by the sums.

"This is the big-government crowd in Washington, D.C., coming in to tell people how to vote," said Sand, a Republican who is running againt U.S. Rep. Earl Pomeroy, D-N.D.

"It's a ridiculous amount of money, all in an effort to stop people from keeping more of the money they earn," Sand said Monday.

Weiler said Measure 1, by setting aside surplus oil taxes in a trust fund, would help protect teachers and public employees from being whipsawed by swings in commodity prices.

"These organizations are the perfect example of groups that are, in the future, going to benefit from this trust fund," Weiler said.

Partners to Protect North Dakota's Future, an umbrella group of organizations opposed to Measures 1 and 2, have filed campaign finance disclosure reports in recent days showing $555,822 in contributions.

The National Education Association has contributed $300,000, while the North Dakota Education Association has contributed $100,822, the reports show.

The North Dakota Public Employees Association has donated $100,000 to the campaign against the two measures, while the American Federation of State, County and Municipal Employees, a national labor union with North Dakota members, has put in $5,000.

Partners to Protect North Dakota's Future has been advertising extensively on radio and television, with one ad implying that approval of the two measures will lead to higher property taxes.

Measure 2's initiative campaign was organized by the North Dakota chapter of Americans for Prosperity, a business-financed group that advocates tax reductions and limits on government.

The measure's backers have disclosed about $35,000 in contributions, including one $20,000 donation from Cincinnati investor Nathan Bachman. Disclosure records show Bachman has supported a number of conservative initiatives and Republican political candidates.

Weiler said Measure 1's supporters have donated close to $50,000.

"We are certainly being outspent in a big way," he said.