WASHINGTON - The agriculture industry, facing a major labor shortage in California and elsewhere of the illegal immigrants on whom growers depend to tend and harvest crops, is making a last-minute push to give undocumented farmworkers temporary status as part of a border-security measure in Congress.

Farm groups are backing a proposal by Sens. Dianne Feinstein, a California Democrat, and Larry Craig, an Idaho Republican, allowing undocumented farmworkers to apply for a ``blue card'' if they can show they worked 150 days during the past two years.

Holders of blue cards would be allowed to work an additional five years, and would have a chance at permanent status if they agree to do farm work for at least three more years. The program would cap blue cards at 1.5 million over five years.

Jack King, director of national affairs for the California Farm Bureau Federation, said his surveys show that the peak-harvest workforce in the state this year of about 500,000 is down 20 percent, with a sharper drop-off for some harvests.

The shortage of temporary farmworkers stems from several factors, observers say. Many have shifted to permanent jobs, such as construction. Tougher border security measures -- and publicity over the deployment of 6,000 National Guard soldiers to assist the Border Patrol -- may have discouraged some seasonal workers from entering the country this year.

Some crops, such as pears in Lake County and strawberries in the Pajaro Valley of Santa Cruz, are being abandoned because farmers can't find enough workers, King said.

With similar shortages in other states, farm groups are pressuring Republicans in Congress to go beyond their "enforcement-only'' approach before the Nov. 7 election and consider relief for growers and farmworkers. But with one week left in the session, that's a long shot.

"We realize that Congress is more concerned with border enforcement right now, and it will be tough to get this through in the next week,'' King said. "But we're going to try.''

During a visit to Congress last week, state growers were told by some California Republicans that an agriculture-jobs measure might be considered during a lame-duck session in November after the election.

Citing the importance of agriculture to California -- a $34 billion industry, producing half the nation's vegetables, fruits and nuts -- Feinstein warned Congress that the labor shortage is urgent.

"There is a crisis,'' she said. "Everyone knows that agricultural labor is virtually dependent on undocumented workers. This is a way to document them, to ensure security and get the workforce for our farming communities.''

In recent days, the House has shown its intent to pursue only border-security measures before the election. The House has refused to negotiate with the Senate over a comprehensive immigration bill, passed by the Senate in May, that includes a path to legal status for many of the nation's estimated 12 million illegal residents.

The Senate bill includes the agriculture-jobs measure, which also has the support of the United Farm Workers.

But the House has focused on such proposals as a 700-mile fence on the Mexican border, which it approved this month for a second time. The fence also was part of a larger immigration package the House approved in December.

The Senate may vote on the fence this week, and Feinstein and Craig urged Majority Leader Bill Frist in a letter Friday to allow a vote on the jobs measure as an amendment.