A Democratic senator said Wednesday he would oppose President Bush's expected proposal to merge the Immigration and Naturalization Service and the Customs Service.

"We ought not visit on Customs the problems of INS," said Sen. Byron Dorgan, D-S.D., at a Senate Budget subcommittee hearing with Bush budget chief Mitch Daniels.

White House aides say Bush probably will recommend the merger of the Justice Department's INS and Border Patrol and the Treasury Department's Customs Service.

The Justice Department would oversee the new agency. Though INS has been under attack for years, Bush advisers say the increased priority on protecting the nation's borders after Sept. 11 gives them political momentum on the issue.

However, the plan would require congressional approval. Several attempts to merge the border agencies have failed in past years.

Bush has not yet made a decision on whether to make the recommendation, Daniels warned.

"If made by the president," Dorgan said, "it would be met with some stiff resistance, and I will be one resisting it."