The United Kingdom’s Labour Party leader Jeremy Corbyn is calling for an investigation into Israeli “interference” in the British government.

The call by Corbyn, whose party has been dogged by allegations of anti-Semitism and anti-Zionism, came following a four-part documentary by Al Jazeera. In the documentary, an undercover reporter filmed an Israeli embassy employee, Shai Masot, discussing his intention to “take down” several British politicians, including Minister of State for Foreign and Commonwealth Affairs Alan Duncan, and calling Foreign Secretary Boris Johnson an “idiot.”

Following the report, Corbyn wrote to U.K. Prime Minister Theresa May that the so-called Israeli influence “undermines the integrity of our democracy.”

“I’m sure you’ll agree that such improper interference in this country’s democratic process is unacceptable, whatever country is involved,” Corbyn wrote. “I would therefore ask that you treat the matter as such and launch an inquiry into the extent of this improper influence.”

In a statement last week, the Israeli Embassy in the U.K. called Masot’s comments “unacceptable” and said he was fired.

"The Embassy of Israel rejects the remarks concerning Minister Duncan, which are completely unacceptable; the comments were made by a junior embassy employee who is not an Israeli diplomat, and who will be ending his term of employment with the embassy shortly," a spokesman said.

At the same time, the British Foreign Office has said it considers the case closed.