Members of the U.K. Labour Party slammed the decision to readmit party member Chris Williamson on Wednesday following a four-month suspension for saying the party has been “too apologetic” about accusations of anti-Semitism.

A panel issued him a formal warning, which ended the investigation, along with the suspension.

“He could face further, more severe, action if he repeats any similar comments or behavior,” a Labour source told The Independent.

Labour leader Jeremy Corbyn said that he was “not involved in the decision” to readmit Williamson.

“I wasn’t involved in the decision at all,” he told ITV News on Thursday. “It was an independent panel set up through the national executive. They examined the case and decided to admit him back in, albeit with a reprimand.”

Nonetheless, Corbyn’s fellow party members expressed “hurt and anger” over Wednesday’s outcome.

“It is clear to us that the Labour Party’s disciplinary process remains mired by the appearance of political interference. This must stop,” reads a statement signed by 144 Labour parliamentarians, who called on Corbyn to “show leadership,” and have this “damaging decision to be overturned and reviewed.”

Labour Deputy Leader Tom Watson told the BBC: “They have taken away a proper disciplinary inquiry that would have got to the facts of this case.”

Independently, more than 70 Labour staff members “have signed a letter to the party’s general secretary Jennie Formby to express their dismay at the decision,” reported the BBC.

In February, Formby said that it “is impossible to eradicate” anti-Semitism, and that it is “dishonest to claim to be able to do so,” though she acknowledged it is crucial to “eliminate the evil of anti-Semitism.”