Two whistleblowers featured in a BBC Panorama investigation into anti-Semitism in the Labour Party have said they now plan to sue the party.
Former officials Sam Matthews and Louise Withers Green said they believed they had been defamed by Labour in its response to their allegations.
The programme – shown on Wednesday – included claims that senior figures including Jeremy Corbyn’s communications chief Seumas Milne and general secretary Jennie Formby – had interfered in anti-Semitism investigations.
In its response, Labour said the allegations came from “disaffected former officials” opposed to Mr Corbyn’s leadership who had “personal and political axes to grind” casting doubt on their “credibility” as sources.
Mark Lewis, the prominent media lawyer who is acting for the pair, told The Observer: “These are very serious libels. Those representing the Labour party have acted in a way that set out to destroy the reputations of the whistleblowers.
“In their effort to destroy these people, they have left it for the courts to decide who is telling the truth. It is ironic that the bosses at the workers’ party have decided to go against the workers.”
Mr Matthews and Ms Withers Green – who broke non-disclosure agreements to speak out – were among eight former party employees featured in the programme.
Mr Matthews told The Observer: “The Labour party is choosing to ignore the central charges of anti-Semitism raised by myself and other whistleblowers on Panorama, and instead, they have engaged in a concerted campaign to damage my name.”
Ms Withers Green told the paper she was “incredibly disappointed” that the party had not taken action on the issues raised in the programme.
“This should be a stark wake-up call about our collective duty to root out racism. But instead the party has used its full weight to discredit us, with untrue, libellous statements,” she said.
Labour denied the comments were defamatory and said it would contest any legal action.
“These are justified statements of opinion. Any claims will be vigorously defended,” a spokesman said.
Labour, meanwhile, continue to contest the Panorama findings, with Jeremy Corbyn claiming it contained “many, many inaccuracies”.
In a speech to the Durham Miners’ Gala on Saturday, he said: “The programme adopted a pre-determined position on its own website before it was broadcast.”
Meanwhile, in a further sign of the tensions within the party, Unite general secretary Len McCluskey launched a blistering attack on deputy leader Tom Watson for criticising Ms Formby for her handling of the issue while she was undergoing treatment for cancer.
“I have a simple message for Tom Watson and his pals in the media – a simple message to Tom and his pals: You should f****** well be ashamed of yourselves,” he said to cheers from the crowd at Durham Racecourse.
“Jennie, our message to you is that the Durham Miners’ Gala stands with you.”