Senate Majority Leader Harry Reid (D-Nev.) acknowledged Tuesday that fierce resistance from Republicans and business groups could force him to delay action on controversial card check legislation sought by unions.

Reid told reporters Tuesday that work on the bill is progressing, but the measure, which would let workers join a union by signing union-issued cards instead of holding a vote by secret ballot, could be completed before the August recess only with Republican help.

“If Republicans will work with us just a little bit, we could get it done before the August recess,— Reid said.

But Republican leaders and the business community have launched a major campaign to kill the legislation. Senate Minority Leader Mitch McConnell (R-Ky.) said he thinks the ultimate chances of passing the measure are “bleak.—

“We’re going to strenuously object to it, fight it in every way and hopefully defeat it,— McConnell said.

Reid effectively needs to run the table to end debate and bring card check to a final vote. He has to hold every Democratic vote, seat Al Franken (D) as the junior Senator from Minnesota and keep the vote of Sen. Arlen Specter (Pa.), the only Republican to vote to end debate the last time the bill came to the floor. All other Republicans are expected to vote against cloture, and GOP leadership blasted the bill in scathing terms as a job killer.

Reid on Tuesday sought to downplay divisions within his own Conference over the legislation, saying that he believes Democrats will remain united on the measure when it does finally come to the floor. “I think, frankly, they’re there,— Reid said when asked if enough Democratic votes could be found to pass the bill.

But even as Reid was speaking before the television cameras, several conservative Democrats expressed concerns about moving forward with the legislation amid an all-out lobbying effort by the business community and in the teeth of the recession.

“It’s a distraction and divisive,— said Sen. Blanche Lincoln (D-Ark.), who said the focus should remain on the economy. “We don’t need to go there.—

“At the present time, I would have difficulty supporting it,— Sen. Ben Nelson (D-Neb.) said. But Nelson suggested he could be persuaded depending on how the bill is amended. “I’m just keeping an open mind on that.—

Fellow Arkansas Sen. Mark Pryor (D) said there could be room for compromise on the issue. “My sense is we can find common ground on this, but we’re not there right now,— he said.

Arkansas is a key battleground because it is home to Wal-Mart, a principal target for unions.

Shortly before Reid spoke on Tuesday, Sen. Tom Harkin (D-Iowa), one of the bill’s sponsors, had said the bill, which is supported by President Barack Obama, could come to the floor next month after the Easter recess.

The bill was introduced Tuesday by Senate Health, Education, Labor and Pensions Chairman Edward Kennedy (D-Mass.) and House Education and Labor Chairman George Miller (D-Calif.).

Harkin said card check would restore balance to the workplace and result in better pay and benefits for workers throughout the economy.

Business opponents argue it would effectively end the secret ballot for unionizing a workplace and allow union officials to intimidate workers into signing up, resulting in higher costs and fewer jobs overall. Opponents complain that once a union is ratified, it would impose onerous new rules forcing quick contract negotiations.

But unions and their Democratic backers say that intimidation by employers is a key reason why unions only represent about 7 percent of the work force.

Harkin said he’s confident Democrats will ultimately climb on board.

“I don’t note any erosion in support for the basic premise,— Harkin said. “I think the votes are there.—

Harkin acknowledged changes to the bill may be necessary to win support.

House Majority Leader Steny Hoyer (D-Md.) said the House would wait for the Senate to act, noting that the House already passed card check in the previous Congress.

House support for the legislation is not in question. Miller said he has 223 co-sponsors for his bill, including three Republicans — more than enough to pass the bill.

But some conservative House Democrats have sought to avoid taking another vote on the issue — one guaranteed to be scored by major business groups as an anti-business vote — unless the Senate acts.

John Stanton contributed to this report.