Corporations and unions can no longer donate to political campaigns in Alberta.

Bill 1, An Act to Renew Democracy, unanimously passed third reading in the legislature Monday night.

The new rule applies retroactively to June 15, the day the bill was tabled in the legislature.

The grandfathered date was put in place on purpose, according to government house leader Brian Mason.

"We didn't want people to be stocking up on major donations with the knowledge that they would soon be disallowed," he said.

The Wildrose says the bill has loopholes which allows unions and corporations to guarantee loans to parties and donate employee time to campaigns.

"The continued existence of these loopholes leaves the appearance that special interests still have a direct hand in influencing and financing the NDP and that goes against the spirit and intent of Bill 1," Wildrose MLA Jason Nixon said in a news release.

Mason said these other issues can be examined via the all-party committee that has been struck to look at ethics and government accountability.