(NewsNation) — Sen. Roger Marshall, R-Kansas, is expected to lead a group of GOP lawmakers to the Senate floor on Tuesday afternoon to call for a vote of no confidence in Homeland Security Secretary Alejandro Mayorkas.

“Our FBI director says all the warning lights are now blinking. This is why we should fire Secretary Mayorkas today,” Marshall said at a news conference.

Marshall believes Mayorkas has broken his oath to enforce the law and protect the U.S. from enemies foreign and domestic. According to the Kansas senator, at least 10 million migrants have illegally crossed the southern border since Mayorkas has taken office.

“He’s derelict in his duties, derelict in the sense he has not maintained operational control of the border,” Marshall said, later adding: “We’ll be on the floor shortly to debate a resolution that is the sentiment of the Senate that we have no confidence in the current secretary.”

This comes after Mayorkas visited the south Texas border in Eagle Pass on Monday and said the migrant situation is out of control, and Congress should act to reform immigration laws.

“Our immigration system is outdated and broken and in need of reform for decades,” he said.

House Republicans are making moves of their own against Mayorkas, with plans to hold an impeachment hearing against him. The hearings are set to begin Wednesday. It would reportedly be a historic event if Mayorkas was ousted, as he would become the first cabinet secretary to be impeached in the last 150 years.

According to reports, more than 300,000 migrants have so far this fiscal year already been encountered on the southern border — which is nearly one-third of all who crossed in Fiscal 2023.

This is a developing story. Refresh for updates.