The Department of Labor’s fiduciary rule will be released on Wednesday, according reports citing unnamed sources familiar with the matter.

In reports published by Politico and the Wall Street Journal on Thursday, sources told reporters that Labor Secretary Thomas Perez will release the final version of the rule on Wednesday at the Center for American Progress in Washington.

Perez will reportedly make the announcement while flanked by some of the rule’s biggest supporters in congress, including Sens. Cory Booker and Elizabeth Warren.

The rule would require all advisors – including broker-dealer representatives – to act in their clients’ best interests when offering retirement investing advice.

The rule was first unveiled by President Barack Obama in February 2015, setting off a period of review and comment highlighted by opposition from much of the financial services industry and some of its congressional allies.

At Politico, writer Patrcik Temple-West predicts that congressional Republicans are likely to challenge the rule via the Congressional Review Act, while Dave Michaels of the Wall Street Journal reports that the American Council of Life Insurers is making preparations to fight the rule in court.