Fellow progressive Democrats expressed anger with President Joe Biden over his authorization of airstrikes against Iran-backed Houthi rebels in Yemen without congressional approval.

Biden on Thursday said U.S. and British forces launched airstrikes in “defensive action” after attacks on shipping in the Red Sea.

Yemen’s Iran-aligned Houthis said on Friday that strikes against the movement by the United States and Britain would not go without “punishment or retaliation.”

The group’s military spokesman said the strikes killed five fighters and wounded six others, and that the Houthis would continue to block the passage of ships in the Red Sea and the Arabian Sea.

Rep. Pramila Jayapal, D-Wash., the head of the Congressional Progressive Caucus, shared The New York Times story reporting the airstrikes and said Biden’s move was “unacceptable.”

“This is an unacceptable violation of the Constitution. Article 1 requires that military action be authorized by Congress,” Jayapal posted on X.

Jayapal was not alone in her criticism of Biden.

“The President’s strikes in Yemen are unconstitutional,” Rep. Ro Khanna, D-Calif., posted Thursday night on X.

“For over a month, he consulted an international coalition to plan them, but never came to Congress to seek authorization as required by Article I of the Constitution. We need to listen to our Gulf allies, pursue de-escalation, and avoid getting into another Middle East war.”

In a personal post on X, Khanna explained, “Section 2C of the War Powers Act is clear: POTUS may only introduce the U.S. into hostilities after Congressional authorization or in a national emergency when the U.S. is under imminent attack. Reporting is not a substitute. This is a retaliatory, offensive strike.”

Rep. Val Hoyle, D-Ore., also took to X and said Biden should have “come to Congress” before authorizing the airstrikes.

“These airstrikes have NOT been authorized by Congress,” Hoyle posted on X. “The Constitution is clear: Congress has the sole authority to authorize military involvement in overseas conflicts. Every president must first come to Congress and ask for military authorization, regardless of party.”

Rep. Cori Bush, D-Mo., a member of the progressive House “Squad,” called the airstrikes “illegal.”

“@POTUS can’t launch airstrikes in Yemen without congressional approval. This is illegal and violates Article I of the Constitution,” Bush wrote on X while sharing an NBC News story on the airstrikes.

“The people do not want more of our taxpayer dollars going to endless war and the killing of civilians. Stop the bombing and do better by us.”

Another “Squad” member, Rep. Rashida Tlaib, D-Mich., also condemned the airstrikes.

“@POTUS is violating Article I of the Constitution by carrying out airstrikes in Yemen without congressional approval. The American people are tired of endless war,” Tlaib wrote on X. ##