Republican presidential candidates Marco Rubio, left, and Jeb Bush at the first Republican presidential debate in August. (Andrew Harnik/AP)

Former Florida governor Jeb Bush, a longtime ally of his state’s wealthy sugar producers, is parting ways with the industry and calling for an end to government subsidies that have boosted company profits for decades.

The move, a surprise to industry lobbyists, could help the Republican’s struggling presidential campaign court conservative activists and competing industries that decry the sugar program as “crony capitalism.”

Bush’s position, confirmed this week by campaign aides, comes as he retools his operation to focus on early-voting states, including Iowa, where the corn industry is preparing to begin an ad campaign attacking the subsidy. His stance puts him at odds with his in-state presidential rival, Sen. Marco Rubio (R), who is being backed by members of the Florida-based Fanjul family, which controls one of the world’s biggest sugar empires.

Bush, who had support from the Fanjuls in past campaigns, now favors “a phaseout of the program,” spokeswoman Kristy Campbell said. She added that Bush “believes we should constantly be moving to reduce government interference and create a level playing field for all commodities on the world market.”

The sugar program has gained importance for some conservative activists, who consider the sugar debate comparable to the ongoing dispute over funding for the Export-Import Bank of the United States, a cause that has rallied hard-core conservatives and tea party activists.

Although Bush aides say the governor has held this view for some time, his position caught activists and lobbyists on both sides of the debate off guard.

Bush has been widely viewed as a sugar industry ally. Sugar companies and executives have donated nearly $600,000 to his campaign, according to the Center for Responsive Politics, a nonpartisan campaign research organization.

“I had never heard [about Bush’s opposition] before, but it describes a difference with the position of the sugar industry,” said Bill O’Conner, a staff member at the Sweetener Users Association, which opposes the sugar subsidy. O’Conner described Bush’s stance as “good news.”

Grover Norquist, president of Americans for Tax Reform, which also opposes the subsidy, described Bush’s position as “a sign of character and commitment to principle.”

Phillip Hayes, a spokesman for the American Sugar Alliance, a leading industry group, declined to say whether he was surprised by Bush’s position. He said Wednesday morning that the industry is grateful for Bush’s past support. “We look forward to learning more about his ideas for U.S. sugar policy as we continue to advocate for a global sugar market that is not grossly distorted by foreign subsidies,” Hayes said.

Rubio has said he only supports an end to the sugar program if other countries stop subsidizing their crops.

“I’m ready to get rid of the loan program for sugar as long as the countries that export sugar into the U.S. get rid of theirs as well,” Rubio said at a meeting held by the conservative Freedom Partners organization in August. Without that guarantee, the United States would effectively turn over food production to other countries, which he said presented a security risk, he said.

Rubio’s position aligns with that of the sugar industry. José “Pepe” Fanjul, whose family’s holdings include the Domino brand and major sugar refineries, has held two fundraisers for Rubio’s campaign, along with his son, Pepito. Their firms have given $200,000 to a pro-Rubio super PAC.

The sugar program, which has existed in various forms since the 1930s, uses a complex system of import quotas, price floors and taxpayer-backed loans to prop up about 4,500 domestic growers.

Sugar advocates say the program is the only way for U.S. sugar to compete in a heavily subsidized international market.

Corn industry executives, whose firms produce corn syrup and other sweeteners for soda and candy, say the program is unnecessary and benefits a competitor, sometimes at taxpayers’ expense.

Public disputes among U.S. commodity groups are rare. But the usually united front collapsed this year as tensions rose between sugar producers and the corn industry, which makes high-fructose corn syrup, a sugar substitute used in soft drinks and baked goods.