Roughly 1.4 million people have been trained to serve as poll workers on Tuesday, about the same as four years ago, according to the U.S. Election Assistance Commission.

But an estimated 2 million will be needed to deal with expected heavy turnout, huge numbers of first-time voters and unfamiliar touch-screen machines in hundreds of counties.

Desperate for workers, the Election Assistance Commission urged businesses and federal agencies to give volunteers the day off with pay to staff the polls.

But as the last deadline for training new workers passed Friday, critical shortages remained in many states.

''If the criminal justice system didn't have access to jurors, the criminal justice system wouldn't exist. Poll workers are just as important as jurors,'' said DeForest Soaries Jr., chairman of the EAC and former New Jersey secretary of state.

The shortage is acute in urban areas where workers should be able to speak multiple languages. Soaries is most worried about New York City, Washington, St. Louis, Chicago and Los Angeles.

Election officials are also struggling to motivate volunteers: For every three poll workers trained, only two show up on election day.

And in Los Angeles County, Registrar Connie McCormack estimates that one-third of the county's past volunteers don't return for a second election.

In March 2002, 125 precincts opened late because no workers were available. The county, the nation's largest, tapped business owners, county workers, leaders of ethnic groups and even high schoolers to find the 25,000 poll workers it will need Tuesday.