"Mitt Romney’s economic plan is just what the country needs to free the private sector and create jobs. It is time for Republicans to unite behind Mitt Romney — he is the candidate best prepared to lead our party and lead the country," Denham said.

Denham will be Romney's 91st congressional endorsement, far outpacing his GOP rivals.

Romney heralded the endorsement in a statement released Tuesday.

“My support is growing in California because voters want a change of direction in Washington,” said Romney. “With the help of leaders like Congressman Denham, we can fix our economy, stop runaway spending, and restore America’s promise.”