An elected representative on the UK’s largest Jewish body has resigned, saying it had “failed to act morally and failed to represent the increasing diversity of opinion within the British Jewish community” amid growing horror at Israel’s renewed assault on Gaza.

Daniel Grossman, one of 36 elected members of the Board of Deputies facing disciplinary proceedings over their criticism of Israel’s actions in Gaza, told a meeting called by the board last weekend that he had “no confidence in the leadership”.

Grossman, 21, a final-year student at Bristol University, was one of three dozen deputies who signed an open letter last month that said “Israel’s soul is being ripped out” by the war in Gaza and that their “Jewish values compel us to stand up and to speak out”.

In response, the board, which consists of more than 300 deputies, opened a disciplinary procedure against all 36 and suspended two deputies. The board’s efforts to shut down debate over the Israeli government’s actions has prompted criticism and discomfort among a significant and growing proportion of British Jews.

Grossman told the Guardian: “It’s very simple: they are refusing to explicitly and publicly condemn Israel’s genocidal assault in Gaza and to criticise the [Israeli] government for abandoning the hostages, who have been in captivity for far too long.

“Increasing numbers of people are recognising that Israel’s actions in Gaza cannot be justified as purely self-defence. They seemingly want to declare a perpetual war against Palestinian civilians with the goal of ethnically cleansing them from the Gaza Strip.”

Grossman said that the past 19 months since Hamas’s horrific attack on Israel on 7 October 2023 had “definitely been a journey for me”. He grew up in a mainstream Jewish community, with strong emotional and familial connections with Israel, but it had become “increasingly clear that the way the Israeli government is acting is not acceptable by any measure”.

The response to his resignation had been more supportive than he expected, he said. “More people were sympathetic than I expected, and it has genuinely astonished me. Lots of these people may not feel able to speak out themselves, they might find it difficult with friends or family. But people have reached out to me.

“A huge shift is happening. The diversity of opinion in the Jewish community is becoming increasingly clear,” Grossman said, yet the board had tried to “stifle dissent”.

Although younger Jews were more open to criticising the actions of the Israeli government, there was not a clear generational divide, he said. “My 89-year-old grandmother, who was a refugee during the Holocaust, said I had done the right thing and she is proud of me for speaking up.”

Grossman said he was on the political left among British Jews, but added: “This issue is touching people across the political spectrum. A lot of people are waking up.”

A spokesperson for the Board of Deputies said: “Daniel’s term as a deputy was due to end in a few weeks with him having been replaced by another representative from the Union of Jewish Students. We wish him well with his future endeavours.”

Its investigation into the 36 signatories to the open letter is expected to conclude in the next few weeks.