Angela Eagle has warned that politicians must take great care in their use of language as she argued that Labour’s leadership candidate, Owen Smith, was right to apologise after suggesting he would like to “smash” the prime minister back on her heels.

In an interview with the Guardian, the Labour MP who stepped aside to allow Smith the opportunity to challenge Jeremy Corbyn alone, said she hadn’t had a chance to discuss the incident with Smith, but added: “He should have and has apologised.”

Asked if politicians needed to be more careful with language, she replied: “As someone that has heard cruel words spoken about me, I know that language matters. And we’ve all got a responsibility to be sensitive with our use of language.

“Owen has shown a capacity to recognise and apologise for insensitivity and that’s important.”

However, she called it “extraordinarily disingenuous” for a Corbyn spokesman to “cloak Jeremy in the mantle of feminism by saying that we have to be sensitive about our use of language, especially around women MPs”.

Eagle said she remembered the controversy in 2014 around comments from Corbyn’s campaign chair, shadow chancellor John McDonnell, and claims that he talked about people wanting to “lynch” then Conservative MP Esther McVey.

In a wide-ranging interview, Eagle also hit out at McDonnell for failing to reach out across the party during her time as shadow business secretary. “I was in the second most important economic ministry – the highest woman, because of the shadow first secretary of state job – and I scheduled a meeting every week with John McDonnell to talk about economics,” she said. “Every single one of them except one, in nine months, was cancelled. Just turned up in the diary cancelled.”

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A spokesman for McDonnell insisted that he had never called for violence against McVey, saying he was reporting comments shouted out by one of her constituents during an event. “It’s something he condemned at the time and he condemns all threats of violence against MPs,” the spokesman said.

He did not deny, however, that meetings had been cancelled, arguing that “like most busy politicians, events in their diaries were regularly being rescheduled”. But he claimed the shadow chancellor had an “open-door policy” to shadow cabinet colleagues, and made his staff available to Eagle and her office.

“In contrast, her office did not always show a willingness to work constructively,” the spokesman added.

Eagle told the Guardian that she was reluctant to talk about abuse and intimidation, including one death threat that resulted in an arrest, since she chose to trigger the contest against Corbyn in the first place, before stepping aside for Smith.

“I don’t want to dwell on it, partially because if I dwell on it too much, or I talk about it too much, I just get a load more,” she said, arguing that much of it had passed, and that she wanted to stay “positive”. She responded to accusations over social media that she and her team had fabricated the details of threats and harassment, suggesting people just needed to look at the internet.

Eagle responded directly to the torrent of abuse about one specific allegation that a brick had been put through her constituency office window on the night after she launched her campaign against Corbyn. The incident has triggered a YouTube video demonstrating that the window was on a stairwell in a communal part of the building, with some questioning if it happened at all.

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“I’ve been in that building for a lot of my 24 years as an MP, it was the night of my launch, we’d never had a brick through the window before. People can draw their own conclusions,” said Eagle. “I didn’t actually say anything. It was reported in my local news and now if you look at Twitter I’m meant to have done it myself, ordered it to be done ... It is a joke. It’s post-truth politics and it’s nonsensical. I’m not a liar.”

Eagle said she was not taking the decision of colleagues to back Smith over her to heart, arguing that taking things too personally could turn a person into a “completely screwed-up individual that hates the world, and I don’t think that is the definition of me”.

Eagle praised Smith for the policy-packed speech earlier in the week, during which he made the gaffe about Theresa May, and spoke about her desire to rebalance the economy in an interview that suggests she could be in line for the shadow chancellorship if Corbyn is beaten.

“The economic circumstances demand that we seek more fundamental solutions than tinkering with the edges of capitalism. We need to fundamentally recast the role of the state in how it supports people throughout their lives, because our lives, our economic lives in particular, are changing at such a rate of knots,” she said.

“He’s not pushing it to the left per se; he’s trying to do what all social democratic parties need to do, which is rebalance our economies and politics to reflect changing times.”