Independent congressional investigators are raising questions about why New Jersey Gov. Chris Christie scrapped the Hudson River rail tunnel project in 2010.

A Government Accountability Office report finds cost estimates for the tunnel had remained unchanged and state transportation officials had said the project would cost less than Christie had estimated. "

Christie had said he feared cost overruns when he canceled what was then the largest public works project in the nation. Tuesday morning, Christie defended halting the ARC tunnel saying "You have to say no."

The GAO also concluded Christie had misstated New Jersey's share of the costs at 70 percent when the state actually was responsible for about 14 percent.

Christie spokesman Michael Drewniak says the 70 percent figure is more accurate because it included funding from the bi-state Port Authority of New York and New Jersey.

The Governor's Office defended the decision to suspend the project. It noted that the projected costs increased from $7.4 billion to $10.9-$13.7 billion in 2010, which was confirmed by the federal government's own assessment. "It was the FTA’s own projections, in an August 2010 memo, that confirmed a rise in projects costs from $8.7 billion to anywhere between $10.9 and $13.7 billion, not including the $775 million Portal Bridge Project that was necessary to complete the ARC project in its entirety," Christie's office said in a statement.

Still, New Jersey Senator Frank Lautenberg, a Democrat, said the ARC tunnel was an important transportation project.

"ARC was critical to the future of New Jersey’s economy and it took years to plan, but Gov. Christie wiped it out with a campaign of public deception," he said. "Construction had already started and thousands of workers were about to be hired when the Governor killed the project.  The future of New Jersey’s commuters was sacrificed for the short term political needs of the Governor.”

With the Associated Press