Questions and answers on immigration

Illegal immigration is a deeply divisive issue in the United States, and a hot political topic. As Congress remains deadlocked over plans to reform immigration law, pro-immigration groups are stepping up their protests against a proposed toughening of the rules.On 1 May they are holding a mass protest called Day Without Immigrants - which includes a call to boycott jobs and schools, and not spend money - to show how much they matter to the US economy.

How big is the problem?
There are thought to be about 11.5 million illegal immigrants in the United States, and each year some 500,000 to a million more enter the country.
Many of these people are poorly educated, unskilled workers, yet in their thousands they fill the sort of jobs that most native-born Americans will not take, at least not for the same price.Much of California's agriculture relies on migrant labour, for example. But some argue these jobs could be filled even without illegal immigrants.

Why is the debate so charged?
Polls suggest that a majority of Americans see illegal immigration as a very serious problem for the US.
Strength of feeling on the issue was illustrated in March 2006 when hundreds of thousands of activists marched in California to protest against plans to criminalise undocumented workers. It has also been reflected in the rise of Minutemen groups - citizens who have taken it upon themselves to patrol the US borders and to confront illegal workers in cities around the US. The issue is also politically awkward for Mr Bush's Republican party, because it brings into conflict two of its core constituencies - social conservatives and the business lobby.

What are the key issues?
The political debate over immigration reform is crystallised around several key issues.These include the enforcement of the country's land borders and existing laws on immigration, changes in the law to deal with people already in the country illegally, and how to offer a regulated route into the US for what the business community says are much-needed workers.Some advocate greatly expanding physical barriers, like fencing, that already exist along some 100 miles of the border near cities - and bringing in tougher penalties for businesses caught employing illegal migrants.Plans for various guest worker programmes, and provisions allowing the millions of illegal immigrants already in the US to remain legally, are also being hotly debated.

What stage is Congress at?
The Senate has been wrestling to pass its own immigration bill, with key players fighting over the guest-worker scheme President Bush has been seeking.Senators also disagree about giving millions of undocumented workers an opportunity to become US citizens.