TRENTON, N.J. (CBSNewYork/AP) — Republican Gov. Chris Christie’s lieutenant governor came out Thursday against a measure Christie supports to ask voters to approve dedicating gas tax proceeds exclusively to transportation projects.

Lt. Gov. Kim Guadagno, in a rare public disagreement with Christie that follows testimony that she had been “frozen out” by the governor, said on New Jersey 101.5FM that she opposes the ballot question.

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“You cannot vote for the question,” said Guadagno, a Republican twice elected with Christie. “That’s the only way to go back and look at where the money is going.”

Christie spokesman Brian Murray said there must be a “misunderstanding.”

“The governor finds it hard to believe that the lieutenant governor supports giving an unguarded pot of money to the Democrat-controlled Legislature rather than on needed infrastructure projects,” Murray said.

The disagreement comes as Christie enters his final year in office, with his approval ratings at record lows. Guadagno is considered a top prospect in the 2017 gubernatorial contest.

At issue is a ballot question before voters on Nov. 8 that asks whether every cent of the state’s gasoline tax, which is being raised from 14.5 cents per gallon to 37.5 cents per gallon next Tuesday, should be dedicated exclusively to transportation.

The state’s transportation fund was so depleted that Christie halted all non-essential projects until lawmakers agreed on a deal.

Guadagno said the problem is that the legislation, which establishes an eight-year, $16 billion transportation trust fund, also requires $12 billion in borrowing. The trust fund measure says the borrowing is contingent on voter approval of the question, but the question doesn’t explicitly seek voter approval for the borrowing.

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Borrowing must be approved by voters, according to a 2008 constitutional amendment, but the trust fund was reauthorized in 2012 without voter approval for more borrowing. Assembly Democratic spokesman Tom Hester said there is an exception for debt that is to be repaid by constitutionally dedicated funds, which the question would authorize.

Assembly Speaker Vincent Prieto, a Democrat, also said Thursday that the lieutenant governor must have a “complete and total misunderstanding” of it.

Christie picked Guadagno as his running mate in the 2009 election, and they were re-elected in 2013. She is the state’s first lieutenant governor, a position that had been filled previously by the Senate president. She also serves as the secretary of state, putting her in charge of elections.

Guadagno has never flouted Christie on such a high-profile issue before. But their relationship has long been thought to be tense and has come up in the federal trial of two former aides to the governor who are charged with closing lanes to the George Washington Bridge as part of a political retribution scheme.

David Wildstein, who has pleaded guilty, testified that the governor and lieutenant have had conflicts.

“I remember being told at least once that she was frozen out,” Wildstein said.

Bridget Kelly, the governor’s former deputy chief of staff who has pleaded not guilty in the scheme, testified that the relationship was “stressful.”

“There were times where she was kind of put in a box (by Christie) and wasn’t permitted to do a whole lot,” Kelly said. “She wasn’t allowed to see his schedule.”

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