Iowa Sen. Tom Harkin, who sponsored a bill making it easier for unions to organize, said a lack of support in the Senate would likely cause the Employee Free Choice Act to be altered.

Harkin told Bloomberg News that the provision of the bill that would give workers the right to unionize as soon as a majority of employees in a workplace signed cards saying they want a union would likely be eliminated.

“Compromises are going to be made,” said Harkin, an Iowa Democrat. “It probably won’t be card-check because too many people are opposed to it now.”

Republicans were joined by several Senate Democrats in opposing the bill, which has drawn the ire of the business community who say that without a secret ballot workers will be intimidated into joining a union.

Supporters of the bill counter that employees already face intimidation from their employer when contemplating a union vote. Under the current law employers can veto workers’ decision to organize through majority signup and force them into the election process where, according to a recent study, a pro-union worker is illegally fired in a quarter of all organizing drives.

In March, Iowa’s senate delegation split on the issue, with Sen. Charles Grassley threatening a filibuster and Harkin saying he was confident he could reach 60 votes to overcome it.

Harkin told Bloomberg a softened version of the bill could garner more support.

“Many do feel there is an imbalance” in current laws that favors business over labor, Harkin said.

“They may not be for the card-check, but they are for changing election process and procedures and shortening the period of time for elections” to form unions in a company.