As presumptive Republican nominee Donald Trump gears up for the general election, Texas Sen. Ted Cruz has returned to Washington, and he’s wasting no time getting back to business.

In a letter addressed to Attorney General Loretta Lynch on Wednesday, Cruz and several other senators blasted the U.S. Department of Justice for their use of law enforcement to silence dissenting voices on climate change. The letter calls out the DOJ for caving to pressure from the left to shut down “climate denial,” citing an oversight hearing in March when Lynch stated, “We have received information about [climate denialists] and have referred it to the FBI.”

The letter also demands that the DOJ cease its efforts to punish dissent:

“We write today to demand that the Department of Justice (DOJ) immediately cease its ongoing use of law enforcement to stifle private debate on one of the most controversial public issues of our time – climate change.”

It also references the attorney general subpoenaing writings and reports from over 100 labs, universities and the like regarding climate change.

The senators slam the DOJ, calling its actions “an abuse of power that rises to the level of prosecutorial misconduct.” They continue to rebuke the DOJ for attempting to silence dissent and obstructing authentic, unbiased scientific research from multiple perspectives.

The letter ends with a mandate that the DOJ address the issue by two weeks, or they will press further action. The clock is ticking.