Major banks and business groups sued the Fed on Tuesday, alleging the U.S. central bank's annual "stress tests" of Wall Street firms violate the law.

The Fed on Monday said it planned to overhaul the stress test regime for banks and planned to seek public comment on planned changes.

Groups representing U.S. banks and businesses said on Tuesday they were suing the Federal Reserve to challenge what they described as the "opaque aspects of the stress testing framework." In a statement,

A lawsuit is expected this week and could come as soon as Tuesday morning, a person familiar with the matter said.