WASHINGTON  The moratorium on deepwater oil and gas drilling imposed after the BP accident has had only modest impacts on jobs and on the Gulf Coast economy, the Obama administration said in a report issued Thursday.

That conclusion, echoing earlier statements by officials defending the drilling pause, was immediately attacked by Louisiana lawmakers and drilling companies, who said it was based on flawed assumptions and incomplete evidence.

The report, prepared over the past two months by administration economists and presented Thursday to the Senate Small Business Committee, found that roughly 2,000 of the 9,700 workers aboard the 46 offshore rigs affected by the moratorium had lost their jobs or moved away from the gulf since the moratorium was imposed in late May.

Another 6,000 to 10,000 workers in associated industries also lost work because of the moratorium, the study found.