WASHINGTON — The Obama administration, under pressure from Congress to weed out government suppliers for ethics violations or poor performance, has proposed to ban almost as many contractors this year as President George W. Bush did in his entire second term.

Federal agencies have proposed blocking 1,006 companies and individuals from contracting so far this year, as well as asking a judge to ban a unit of food-processing giant Cargill Inc. of Minneapolis, in a process known as debarment. That is 16 percent more than the 868 contractors that government agencies proposed to block in all of 2010, and only 70 fewer than the 1,076 contractors that U.S. agencies sought to debar under Bush from 2005 to 2008, according to data provided by the General Services Administration.

Federal agencies are under pressure after a series of congressional hearings and reports from inspectors general and the Government Accountability Office faulted procurement officials for failing to keep unqualified or ineligible vendors out of the $500 billion-a-year federal market.

“We are starting to see the pendulum swing to more contractor accountability, but government needs to do a lot more to ensure it only works with responsible contractors and thereby protects the public,” said Scott Amey, general counsel for the Project on Government Oversight, a nonprofit watchdog group.

The proposed debarments appear to be the most since at least 1997, the earliest year comparable data was available, and may be a record, said Meredith Whitehead, a project manager with the General Services Administration, which oversees the online database used to track contractors barred from winning government work.

Federal spending on contracts for goods and services has more than doubled since 2000, to $534 billion in the fiscal year ended Sept. 30, 2010 from $213 billion in the fiscal year ended Sept. 30, 2000.