Administration officials yesterday offered details of President George W. Bush's proposal for a temporary guest worker programme but faced criticism from some Republicans, who argue the approach would reward people who are in the US illegally.

Michael Chertoff, homeland security secretary, sought to reassure sceptics that the proposal would not offer amnesty to those in the country illegally. Instead, he told the Senate judiciary committee, it would "regularise" the existing situation, channelling some of the estimated 10m illegal immigrants in the US into a system that improves conditions for workers and their employers and "will ultimately get them back to their own countries".