Labour‘s general secretary has accused its deputy leader, Tom Watson, of ”publicly attacking” her during her cancer treatment after he criticised the party’s “deplorable” treatment of whistleblowers.

Jennie Formby hit back at Mr Watson, branding him “deeply irresponsible” and his actions “inappropriate”, as the row between senior figures in the party deepened following new revelations about its handling of antisemitism,

She claimed Jeremy Corbyn’s deputy was abusing his position and “traducing” her reputation while she undergoes chemotherapy.

Mr Watson had earlier written to her to raise concerns about the party’s treatment of employees who had spoken out about antisemitism.

As the backlash from the revelations contained in a BBC documentary continued, Ms Formby wrote back, saying she was “very disappointed” by Mr Watson’s behaviour.

Protests against Labour antisemitism Show all 14 1 /14 Protests against Labour antisemitism Protests against Labour antisemitism Protesters clashed during the demonstration Reuters Protests against Labour antisemitism Members of the Jewish community hold a protest against Labour party leader Jeremy Corbyn and antisemitism in the Labour Party AFP/Getty Protests against Labour antisemitism Protesters hold placards and flags during a demonstration, organised by the British Board of Jewish Deputies for those who oppose antisemitism, in Parliament Square Reuters Protests against Labour antisemitism Hundreds of people gathered in Parliament Square to protest against antisemitism in the Labour Party EPA Protests against Labour antisemitism Labour MP Luciana Berger speaks during the protest PA Protests against Labour antisemitism A protester blows through a shofar during the demonstration Getty Protests against Labour antisemitism Members of London's Jewish community protest in support of Labour leader Jeremy Corbyn outside parliament EPA Protests against Labour antisemitism Labour MP John Mann speaks during a protest against antisemitism PA Protests against Labour antisemitism People protest against antisemitism in the Labour Party as Jewish community leaders have launched a scathing attack on Jeremy Corbyn, claiming he has sided with antisemites ‘again and again’ PA Protests against Labour antisemitism Labour politicians Stella Creasy and Chuka Umunna leave after attending the demonstration Getty Protests against Labour antisemitism A pro-Jeremy Corbyn protester holds a placard during a counter-protest Getty Protests against Labour antisemitism A support of the Labour Party hold up a placard during the demonstration Reuters Protests against Labour antisemitism Jeremy Corbyn supporters during the demo Reuters Protests against Labour antisemitism A protester holds up a sign reading ‘For the many, not the Jew’ AFP

“I am very disappointed at the way you choose to address this extremely sensitive and difficult issue. The party has at all levels consistently shown that it recognises the vital importance of combating antisemitism, yet you consistently abuse your considerable platform to denigrate any progress that has been made, and any individual that is involved in that”, she wrote.

“Furthermore, traducing my reputation and publicly attacking me when you know I am undergoing chemotherapy and am unable to respond in the media, is another example of the inappropriate way in which you choose to discuss this issue.”

The latest row broke out in the wake of a BBC Panorama investigation into Labour’s handling of antisemitism, which featured former party employees speaking out about their experiences.

The whistleblowers claimed they had been obstructed in their attempts to tackle antisemitism, and some said they had suffered mental health problems because of the difficulties they encountered at work.

Ms Formby told Mr Watson that she was “very concerned to hear for the first time the distress suffered by some of our former staff members” but accused him of commenting “uncritically” on the programme.

She said: “By choosing to ignore the steps taken by this party, and commenting so uncritically about the Panorama programme, you are complicit in creating a perception that antisemitism is more prevalent in the Labour Party than wider society.

“This is deeply irresponsible for the deputy leader of a party which seeks to be in government, and risks exacerbating the feat that Jewish communities will feel.”

John McDonnell, the shadow chancellor, also criticised Mr Watson, saying it “goes beyond my understanding” that he had written to Ms Formby ”when he knows she’s undergoing chemotherapy”.

“I just don’t understand why the deputy leader of the Labour Party uses the media to demand information from Labour’s general secretary, which has already been offered to him,” he tweeted.

In his letter, Mr Watson said the way the whistleblowers had been “smeared” by Labour spokespeople was “deplorable”.

“Even if some in the party did not want to hear what they had to say, it is unacceptable to attempt to undermine their integrity and characters in this manner,” he wrote.

He also insisted that Labour’s response to the Equality and Human Rights Commission’s investigation into antisemitism in the party should be made public because “only sunlight can disinfect Labour of antisemitism now”.

Ms Formby responded that she had twice offered to show Mr Watson the party’s response.

The Panorama documentary included the testimony of eight former Labour employees, four of whom broke non-disclosure agreements (NDAs) to speak out.

The former officials claimed that Mr Corbyn’s allies, including Seumas Milne, his director of communications, and Ms Formby had interfered with investigations.