U.S. Trade Representative Rob Portman won a unanimous endorsement Tuesday from the Senate Budget Committee to head the White House budget office.

Portman, a former GOP representative from Cincinnati, would replace White House Chief of Staff Joshua Bolten as director of the Office of Management and Budget.

Portman is a longtime Bush loyalist and was one of President Bush's top allies on Capitol Hill. His nomination now goes before the full Senate, which may confirm Portman as early as this week.

He faced a challenging year as trade representative. He was key to finessing House passage of the Central American Free Trade Agreement last year but has had less success in pushing an ongoing round of global trade negotiations.

Senate Budget Committee Chairman Judd Gregg, R-N.H., twice postponed votes on Portman last week, leading to widespread speculation on Capitol Hill that he was holding up the nomination to gain leverage in talks over a border security package that is part of a Senate-passed Iraq war and hurricane relief funding bill.

Gregg did not deny those rumors last week but relented and held the vote despite his irritation at the White House, which last week submitted a $1.9 billion border security initiative that is substantially different from the version drafted by Gregg in the Senate.

The White House emphasized additional manpower, while Gregg focused on capital needs such as new helicopters, planes and ships for the Border Patrol and Coast Guard.