The U.S. Treasury Department is investigating whether Wall Street firms may have understated their profits in the first quarter as it seeks to lower the federal minimum wage to $15 an hour by 2022.

The investigation comes as the White House announced it would cut the corporate tax rate to 28 percent in its budget blueprint, a proposal that will hit the top earners hardest.

Wall Street and the GOP-controlled House of Representatives have been pushing for higher corporate taxes, arguing they are a vital part of a strategy to keep corporate profits high.

The Obama administration says it’s investigating whether firms have overstated their profit margins.

“The Federal Reserve is currently evaluating the impact of higher minimum wages and the implementation of other measures on the labor market,” Treasury Secretary Timothy Geithner said in a statement Thursday.

“The Department is working to determine the extent to which these additional measures could impact employment and wage growth in the economy.

The White House says the Treasury is not investigating the potential impact of these minimum wage increases on the federal budget, which would likely be a lower priority for the Trump administration.

The Treasury Department also says it is looking into whether some firms have underreported their profits to the IRS, as well as whether some companies are making false claims about their profits.

The Treasury Department has said it has launched a wide-ranging review of its tax policies.