An MP described by his former chief of staff as “the most disgustingly morally bankrupt person I have ever had the displeasure of working with” is under increasing pressure to step down after claims he is failing his constituents.

Jared O’Mara, who ousted Nick Clegg in Sheffield Hallam in one of the big surprises of the 2017 general election, was described as a “selfish, degenerate prick” by Gareth Arnold in a very public resignation on Tuesday night.

Arnold posted a stream of tweets aimed at O’Mara using the MP’s own Twitter account, accusing him of not caring about his constituents and having “a vile, inexcusable contempt for the people who voted you in”.

In Sheffield, many constituents demanded O’Mara, who sits as an independent, stand down. But some MPs urged compassion for O’Mara, who has spoken of making suicide attempts after being suspended from the Labour party when a series of sexist and homophobic tweets emerged, written before he was elected.

Toby Perkins, the Labour MP for Chesterfield, near Sheffield, tweeted: “To all those who are enjoying this character assassination and whilst appreciating that Jared hasn’t covered himself in glory, this is not right. Just because he’s an MP doesn’t mean he’s not a human being.”

Another Labour MP, Jess Philipps, said: “I’m sure he is an awful MP and probably not a good boss, but it sounds to me like he’s really unwell and deserves help.”

Arnold, who has a history of online pranks, is an old friend of O’Mara’s from Sheffield’s nightlife scene and began working for him eight weeks ago.

After coming in for criticism for resigning so publicly, Arnold insisted on Twitter that “all other avenues have been explored”. The Guardian understands he even cold-called the Liberal Democrats’ office in Sheffield last week and raised a number of “serious concerns”, saying he was going to quit.

There was no answer when the Guardian attended O’Mara’s constituency office on Wednesday. A receptionist in the city centre building said there was no one in his office. O’Mara has not been seen in public since Arnold’s resignation but told the Mirror he needed “to get to the bottom of the matter” and would comment once he had “ascertained what’s going on”.

Louise Wilcockson, a prominent environmental campaigner who lives in O’Mara’s constituency, said that after a series of controversies, which began in October 2017 when he was suspended from the Labour party, “trust has been completely eroded”.

O’Mara quit Labour in July last year and announced he would be carrying on as an independent, refusing to call a byelection.

Wilcockson, a former teacher, said she had been hopeful O’Mara would “empathise with the most vulnerable in society” given his own disabilities. However, she said his constituents had been let down.

“It’s just been one shocking saga after another,” she said. “Now he’s not even Labour but independent, so his Labour voters didn’t get what they voted for either. And this is what we lost Nick Clegg for? We need to demand better.”

Laura Gordon, who has been the Liberal Democrats’ parliamentary candidate for Hallam since November 2017, said she was sympathetic about O’Mara’s health problems but Arnold’s allegations raised “real issues”.

She said: “We don’t know whether everything Gareth Arnold has claimed is true, but at the same time Jared has a responsibility to his constituencies. It’s a responsibility that he chose to make when he was elected and at the moment he isn’t fulfilling that responsibility. There are people in urgent situations in Hallam who need an MP to help them and by not doing his job he is learning vulnerable people in the lurch.”

Gordon claimed constituents had come to her for help after failing to get meetings with O’Mara. “We have done what we can to help but there is only so much you can do without the office of an MP.”

In March, two aides who had been with O’Mara since his election resigned. Shortly afterwards, O’Mara sacked two members of staff including Margaret Flude, his office manager, who promptly announced she would be taking him to an industrial tribunal. The case is due to be heard in September. A fifth member of staff left in solidarity and O’Mara’s office was shut for a month.

O’Mara reopened his office in May with new staff including Arnold, telling the BBC he would “rise like a phoenix from the flames”. But he continued to receive criticism for missing key votes in the Commons, particularly related to Brexit.

In a blogpost on his own website, O’Mara said he would continue to be absent because of physical health problems. “I have a slipped disc in my back, a torn bicep in my left arm and cerebral palsy in my right arm. I am forced into wearing a vest and elasticated shorts. My general mobility is laughable,” he wrote.



The Guardian understands that parliament made numerous accommodations for O’Mara’s disabilities, including allocating him an office close to the debating chamber, which until Ed Miliband’s departure in 2015 was reserved for the leader of the opposition.

John Bercow, the Speaker, gave O’Mara special dispensation to not wear a tie in the chamber, and O’Mara was allowed to take Uber taxis instead of the tube because he struggles with stairs and crowded places.

In Sheffield, staff arranged for many constituency surgeries to be held in the fully accessible Ecclesall Library, only for O’Mara to cancel at the last minute.

• This article was amended on 25 July 2019. An earlier version incorrectly said that O’Mara’s “phoenix from the flames” quote was given to the Mirror.