Thousands of workers gathered on Capitol Hill Wednesday urging Congress to pass the Employee Free Choice Act (EFCA), a controversial bill that would make it easier for unions to organize.

Under EFCA, a union would be certified by the National Labor Relations Board when a majority of employees have signed cards creating a bargaining authority. The bill would eliminate secret ballot elections for establishing unions, which EFCA supporters argue give employers leeway to intimidate employees into rejecting the union.

The rally is a culmination of the Million Member Mobilization initiative through which representatives across unions gathered 1.5 million signatures in support of the bill.