The Parliamentary Labour Party (PLP) executive committee will write to the seven ex-Labour staffers who appeared on the documentary to say they back them in speaking out.
The decision came after a fractious meeting of the PLP in Westminster last night over the anti-Semitism crisis engulfing the party and how the former party employees have been treated by the Labour leadership.
Labour MP Wes Streeting, vice-chairman on the All Party Parliamentary Group on British Jews, said: “It’s important MPs show the whistleblowers that we are appalled by what happened and are not letting this go.”
The letter will come from PLP chairman John Cryer and vice-chairwoman Ruth Smeeth, who proposed it, and will say that MPs and peers in the parliamentary party support their right to speak out and lift the lid on the way anti-Semitism cases are handled.
Jeremy Corbyn also sits on the committee. It is understood the letter will be sent regardless of whether it has his signature or not. It comes after Mr Corbyn agreed to hold an emergency meeting of his shadow cabinet next Monday to discuss the crisis.
Last Wednesday’s Panorama programme saw Corbyn allies, general secretary and trade unionist Jennie Formby and Seumas Milne, accused of allegedly intervening in cases of anti-Semitism by members.
Sam Matthews, the party’s former head of disputes, was in the programme and revealed he had contemplated suicide because of the stress of dealing with anti-Semitism cases.
Labour threatened him with legal action for breaking the terms of a non-disclosure agreement.
The party have said they officially complained to the BBC about the programme, describing it as “one-sided, with no political balance”, “quotes invented” and “emails edited to change meanings”.
It comes as Lord Harris of Haringey, a former London Assembly member and chairman of the Labour peers group, told the BBC that Mr Corbyn should have “reigned back some of his more idiotic supporters and stopped them doing some of the things they are doing”.
A Labour Party spokesman said: “There is no evidence of Jeremy Corbyn’s office interfering in cases.
“The party’s records show that since September 2015, the number of cases that have undergone disciplinary procedures relate to about 0.06 per cent of members, with the rate cases are dealt with increasing more than four-fold under Jennie Formby’s tenure as General Secretary.”