WASHINGTON – Whether you label it the “card-check” bill or the Employee Free Choice Act, you can also call it something else: in deep trouble.

Key senators this week appeared to cripple prospects for passing the highly polarizing measure, the labor movement’s top priority in Congress, which is aimed at making it easier for workers to join unions.

The latest hurdle came Friday, when Sen. Dianne Feinstein, D-Calif., said she would seek alternative legislation that was less divisive. Feinstein, a past sponsor of the act, cited the flailing economy as a reason; other critics have said it would drive up operating costs for businesses at a perilous time.

“This is an extraordinarily difficult economy, and feelings are very strong on both sides of the issue,” Feinstein said in a statement. “I would hope there is some way to find common ground that would be agreeable to both business and labor.”

Feinstein’s words came days after Sen. Arlen Specter, R-Pa., declared he would not support the bill. Specter also previously supported the act, and his announcement was viewed as eliminating any chance to break a promised Republican filibuster.

The card-check bill would bypass the traditional election process and allow workers to be certified as a bargaining unit if a majority signed a card indicating their support for a union. The proposal played a leading role in congressional campaigns across the country.

Now its supporters are scrambling to figure out their next move. It appears that if the legislation has a future, it will not be in its present form.

“We knew all along that this bill would be amended. It seems clear now we’ll have to look at some changes to get to the floor,” said Sen. Tom Harkin, D-Iowa, a co-sponsor of the legislation.

Supporters see card check as a way to improve wages and benefits for workers, who in turn would pump more disposable income into the economy.

“Passing the Employee Free Choice Act would be like a mini-economic stimulus package – pumping approximately $49 billion into the economy each year at a time when working families need it most,” said Christy Setzer of the Service Employees International Union.

Opponents, including some of the most powerful business lobbies in Washington, say it would devastate businesses and that it amounts to a political-power grab by union interests such as the AFL-CIO.

Although the card-check provision has drawn the most attention, opponents are just as concerned about language that would require compulsory arbitration if management and the newly certified unit could not agree on a collective bargaining agreement within four months.

They say that would allow the government to force unwanted contract provisions on companies, increasing costs. Proponents say the provision would encourage companies to strike contracts with unions quickly.

All along, Republicans have made it clear they would stop the bill with a filibuster if they could. Specter’s announcement Tuesday meant all 41 Republican in the Senate are now lined up against the bill.

Some moderate Democrats are not behind the bill. Sen. Ben Nelson, D-Neb., for example, has come out strongly against the measure.

A majority of Democrats in the House support the bill, but leadership there won’t force a politically sensitive floor vote if there is no chance the legislation can clear the Senate.

Although unions say they are somewhat open to a compromise bill, they insist that it must include provisions that make organizing easier, force companies to negotiate contracts quickly and increase penalties against employers for retaliating against union organizers.

Last week, the executives of three companies known for their progressive image, Costco, Starbucks and Whole Foods, offered what they termed a “third way.”

It would eliminate the binding arbitration provision and preserve the right of management to demand a secret ballot election when workers seek to form bargaining units. But it also would shorten the period management would have to campaign against unionization.