Labour has been accused by the Board of Deputies of British Jews of “letting off” people accused of antisemitism without sanction, after a leaked draft of the party’s disciplinary process showed that some members can avoid punishment in serious cases where they have apologised and agreed to undergo education.

The Board of Deputies, a leading Jewish organisation, said Labour’s disciplinary processes were still not good enough and appeared too permissive towards antisemites, following the emergence of a draft of the party’s “antisemitism decision-making matrix” from March.

But Labour defended itself, saying all cases were reviewed on the basis of evidence and arguing that it was right to adjust sanctions depending on the member’s acceptance of culpability. It is understood that the party does not treat an apology as an automatically mitigating factor or as a reason for not imposing a sanction.

The matrix, seen by the Guardian, says: “If there is a case to answer that the member has breached the rules, decide whether a) the alleged conduct is too serious to be disciplined with a written warning (ie suspension or expulsion appears appropriate, or b) there is an important dispute of fact. If so, refer to the NCC (unless education appropriate/agreed, and with acknowledgement/apology, is sufficient mitigation).”

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It adds: “If the conduct would have been serious enough for referral to the NCC [national constitutional committee] or an NEC [national executive committee] warning but member has acknowledged/apologised and agreed to education, record agreement to education.”

Labour said all cases were reviewed based on the available evidence. A party spokeswoman said: “For example, an individual’s refusal to recognise their wrongdoing is likely to result in a more severe sanction.

“The Labour party is taking decisive action against antisemitism, swiftly suspending and imposing robust sanctions on individuals. Since Jennie Formby became general secretary, the number of staff dedicated to dealing with complaints and investigations has been doubled and the rate at which cases are dealt with has increased more than fourfold.”

However, Marie van der Zyl, the president of the Board of Deputies, said: “Despite Labour’s protestations after the Panorama programme, it is clear that Labour’s disciplinary processes still seem to be more geared towards protecting antisemites than protecting Jews. Over and over again, we see known and repeat offenders being let off despite a massive burden of evidence.

“The option of apology or training for those with serious enough cases to be referred to the national constitutional committee to get off is nothing better than a ‘get out of jail free card’ for racists. Fundamentally, this is about the culture and leadership of the party under Jeremy Corbyn being too permissive to antisemites. The process is wrong, the practice is wrong and the culture is wrong.”

Separately, the Board of Deputies wrote to all MPs and members of the national executive committee ahead of a special shadow cabinet meeting on Monday, calling for a more independent disciplinary procedure and for the cases of two high-profile members under investigation, Chris Williamson and Peter Willsman, to be dealt with within a fortnight.

The Jewish Leadership Council has also written to shadow cabinet ministers calling for an independent disciplinary system to be brought in and saying they must not underestimate the importance of Monday’s meeting as “inaction will signal your support for what has happened and what will follow”.

The interventions come after a difficult couple of weeks for Labour, since the broadcast of a BBC Panorama documentary in which eight former staff members alleged that the party was not dealing properly with complaints of antisemitism and was allowing Corbyn’s office to get involved in disputes.

Labour strongly denied any interference by the leader’s office, complained to the BBC, and said the claims were made by “disaffected former officials including those who have always opposed Jeremy Corbyn’s leadership, worked to actively undermine it, and have both personal and political axes to grind”.

However, there has been an outcry from some in the party, including Tom Watson, the deputy leader, whose relations with the leadership are at a low point.

More than 60 Labour peers took out an advertisement accusing Corbyn of having “failed the test of leadership” over his handling of antisemitism complaints within the party, and Labour’s leaders in the House of Lords issued a veiled challenge to Corbyn’s authority on Monday by warning him that antisemitism was a “cancer that will continue to grow”.

Meanwhile, more than 200 Labour supporters – half of them current or former Labour staffers – demanded an explanation from party bosses over the treatment of the Panorama whistleblowers.

Labour is to hold an extraordinary shadow cabinet meeting on Monday to address concerns about antisemitism, and Corbyn will address MPs on the issue the same day.