Administration officials could face fines or jail time for ignoring congressional subpoenas, as House Democrats say they’re seriously considering reviving a congressional power that has not been used since the 1930s.

President Donald Trump has publicly urged administration officials not to comply with congressional subpoenas, and some have started heeding the advice. House Democrats have made no formal decisions about how to respond to the Trump administration’s stonewalling of their oversight investigations, but one option on the table is the historical process of “inherent contempt.”

“There is no tool in our toolbox that we should not explore,” Oversight and Reform Chairman Elijah E. Cummings said Tuesday.

That includes using Congress’ inherent contempt power to impose fines or jail time for administration officials who refuse to comply with congressional oversight requests, the Maryland Democrat said.

The possibilities are becoming less abstract. Attorney General William Barr has sparred with the House Judiciary Committee about the parameters of testifying this week on the report by special counsel Robert S. Mueller III on Russian interference in the 2016 election. And there are several other instances of the administration and Congress clashing over the legislative branch’s oversight protocols.