Last Updated: Monday, 1 May 2006, 15:01 GMT 16:01 UK
Immigration rally in Washington
Immigrant workers in the United States are staging a day of nationwide action in another protest against proposed immigration reform.
Millions are expected to stay away from work and school, and avoid spending money, in an effort to show how much immigrants matter to the economy.
Called A Day Without Immigrants, the protest comes as Congress wrestles with reform of immigration laws.
About 11.5m illegal immigrants live in the US, many entering via Mexico.
Some commentators say the emerging immigrant movement - the force of which was evident at nationwide demonstrations last month - can be compared with the civil rights protests of the 1960s and 70s.
Monday is a normal working day in the US.
Yet Latino leaders are saying that the scale of what will happen is hard to predict.
Some will work but buy nothing. Others will protest at lunch breaks, school walkouts or at rallies after work. There are planned church services, candlelight vigils, picnics and human chains.
But there are fears the action may trigger a backlash and some are questioning how many people will actually participate in the boycott.
The protest is also expected to spread to Mexico and other Latin American countries, where people have been urged to boycott US products for the day.
In some of the protests:
* Supporters in New York will form a human chain at 1216 (1616 GMT) to symbolise 16 December 2005 - the day controversial immigration bill was passed in the House of Representatives - followed later by a rally in Union Square at 1600
* In Chicago up to half a million people are expected to attend a demonstration in Grant Park
* In California, which has more undocumented workers than any other state, mass rallies will be held, the largest expected to be in Los Angeles
* Goya Foods will halt distribution for the day, while Tyson Foods, the world's largest meat producer, will shut nine of its 15 plants.
In California the State Senate approved what lawmakers called "the great American boycott of 2006", describing it as an attempt to educate Americans about "the tremendous contribution immigrants make on a daily basis to our society and economy".
Giev Kashkooli, from the United Farm Workers' Union, told the BBC: "They are people who are working, who share the values that other Americans share. They're farm workers who are feeding the nation."
The protest comes with the US Congress caught up in the divisive business of reforming immigration laws.
Right-wingers believe too much emphasis has been placed on plans for illegal immigrants to gain citizenship and not enough on enforcing current laws.
A bipartisan bill currently stalled in the Senate would bolster border security, but also provide illegal immigrants a path toward citizenship and a guest-worker programme long favoured by President George W Bush.