Opposition to a compromise US immigration bill is growing in Washington.
The deal was hailed by groups lobbying for recognition for undocumented Irish living in the United States, but trade unions and Hispanic groups say the deal was bad for workers, families and employers.
The League of United Latin American Citizens, one of the country's oldest and largest Hispanic groups, said it opposed the plan's limits on family-based immigration.
"This bill will dehumanise workers, short-change employers and lead to widespread undocumented immigration as many workers inevitably overstay their visas rather than return home," the group's president, Rosa Rosales, said.
A union and another Hispanic group said they would work to change the proposed law as it moves through Congress.
The opposition emerged as the Senate began debating the compromise plan, brokered in closed-door talks between White House officials and about a dozen Republican and Democratic senators.
President Bush, pleaded with opponents to read the bill properly before offering opinions. "There's no question this is an emotional debate. But people have to realise that in order to have border security, you must have a comprehensive approach to immigration reform," Mr Bush said.
The measure would combine tough new border security and workplace enforcement measures with a temporary worker programme and a plan to legalise an estimated 12 million illegal immigrants who arrived in the United States before January 2007.
Dozens of amendments are expected to the bill, and it is unclear whether the compromise will remain intact as it works its way through the Senate.