Nigel Farage was told by a senior Reform official that he was “protecting” a high-profile mayoral candidate accused of making racists comments about David Lammy, an undercover investigation has revealed.

The latest footage from an undercover investigation by ITV also shows Sarah Pochin, one of two female MPs for Reform, complaining that other party officials “are so fucking chauvinistic” and that “they just exclude you if you are a woman”.

Other footage shows Farage himself discussing the case of Chris Parry, a retired rear admiral picked to contest Hampshire and the Solent mayoral election for the party.

The party stood by Parry for months after it emerged that he had said the former foreign secretary should “go home to the Caribbean” last year, and suggested that at least eight other politicians from minority ethnic backgrounds do not have a primary loyalty towards the UK.

However, while Reform eventually suspended him in March after the Guardian revealed other remarks by Parry, clips from an ITV documentary show Farage pushing back against senior advisers who said the candidate had to be sacked. They included Ed Sumner, Reform’s head of communications, who had told another press officer in an earlier disucussion that Parry was “clearly a racist”.

“He needs to go, I’m getting rid of him,” Sumner was filmed saying when the controversy broke last December. However, Parry was still the candidate three weeks later, while Farage told a press conference that the candidate could stay if he apologised.

In a conversation between Farage and Sumner, which was recorded by the undercover reporter, the Reform leader said that Parry “must apologise to Lammy” and was told that a text had been written for the candidate.

“He must do it and move on … Tell him that from me,” Farage said, to which Sumner said: “You’re protecting him.”

To laughter, Farage replied: “It’s showing a bit of … bit of sorrow. Look, ‘I’m sorry’ is probably a good thing to hear. Just take the fucking deal. Trouble is he’s a rear admiral. That’s the problem.”

Parry was suspended on 26 March after the Guardian reported that he had described members of a Jewish neighbourhood watch group as “cosplayers” and likened them to “Islamists on horseback”.

Bridget Phillipson, the Labour party chair, said these “latest shocking and deeply disturbing revelations go right to the top of Reform”, adding: “Nigel Farage needs to wake up and realise the buck stops with him. He also must urgently explain why he allegedly stood by a blatant racist instead of kicking him out of his party.”

The revelations are the latest in a number of recent controversies for Reform. The full ITV documentary, Undercover: A Year in Reform, airs on Sunday.

A number of councillors have already stood down after segments from the investigation aired on Wednesday showed them making graphic threats of extreme violence and expressing racist and misogynistic views.

The undercover reporter for ITV also met Pochin, Reform’s MP for Runcorn and Helsby, at a time when she was the party’s only female member of parliament.

When Pochin was told that a new female press officer was starting work, she was recorded as saying: “Oh thank fuck for that. God! We so need women press officers … They are so fucking chauvinistic.

“I go out on all the shows and go: ‘Oh no, it’s lovely, oh they’re all so welcoming.’ Shit … they just exclude you if you’re a woman. It’s really tough being a girl with all of this alpha male shit going on.”

Pochin did not provide a statement when approached by ITV. Reform UK used a statement issued on Thursday to accuse ITV and the company behind the documentary, Hardcash Productions, of using “extreme methods of deception”.

It said: “They have infiltrated our workplace including commissioning an undercover journalist to provide altered identification documents, a false address, and false credentials so that they could be given access to Reform’s headquarters, computer systems, and spy on its employees.

“That same journalist did not limit themselves to recording candid conversations in the workplace. That journalist also sought to find out sensitive security information, travel arrangements, and financial information outside of the scope of this investigation.”

Reform went on to claim that ITV had failed to address this in correspondence, despite this conduct being drawn to their attention. “This is at a time when Nigel Farage and other members of Reform are being targeted by individuals who wished them harm and caused a security issue which was documented during the course of the undercover investigation,” it added.

“There is no room for racism in Reform UK. We always respect due process of investigations and whilst these are ongoing it would not be appropriate to comment on individual cases.”

When approached for comment, Parry referred the Guardian to a statement given to ITV. In it he said: “I would urge people to go back to the original contexts and tweets to see what was said and why. They related to reparations and failures by the police and government. They will see I always exercise my right to criticise anyone in power or the public eye whom I judge to be acting against the interests of the British people.”