Arron Banks, the biggest donor to Ukip, has said that he is “sick to death of hearing about” the Hillsborough stadium disaster in which 96 people died, describing it as an “awful accident” that “could have happened anywhere, anytime” in the 1980s. He also accused one of his critics of “milking a tragedy forever”.

The millionaire businessman was reacting to a tweet on Tuesday by the Daily Mirror columnist Brian Reade after Paul Nuttall, Ukip’s leader, admitted that claims on his website that he had lost close friends in the disaster were false.

After Reade criticised Nuttall, Banks replied:

I'm sick to death of hearing about it. It was a disaster and that's it, not some sort of cultural happening https://t.co/KTJPosOGDo — Arron Banks (@Arron_banks) February 14, 2017

After Reade remarked that he was “sorry you’re sick” of hearing about the disaster, Banks went on:

No milking a tragedy forever is sick https://t.co/t1AHg6WJqb — Arron Banks (@Arron_banks) February 14, 2017

if a policemen opens a gate trying to help and makes a bad decision it's an accident. As for a cover up it was the 80's. https://t.co/shIMzVXNoL — Arron Banks (@Arron_banks) February 14, 2017

It was the 80's , I been at some matches that were squeezed beyond belief. This could have happened anywhere anytime. https://t.co/W8gAyZYr5Q — Arron Banks (@Arron_banks) February 14, 2017

Banks’s comments were greeted with disbelief by Hillsborough campaigners. Charlotte Hennessey, whose father, James, died in the disaster, tweeted:

It was a completely preventable disaster caused by gross neglience that resulted in 96 people unlawfully killed. Actually. https://t.co/5nv21R3UST — Charl JFT96 Hennessy (@charlhennessy1) February 14, 2017

Nuttall’s admission, on Liverpool’s Radio City News, that the statement on his website was false came four days after the Guardian reported that the MEP had denied lying about being at Hillsborough on the day of the 1989 disaster. When shown the 2012 article on his website claiming that he had lost “close personal friends” in the tragedy, he said: “I’m sorry about that, but that is something … I haven’t put that out. That is wrong.”

In another tweet, Banks said that “overcrowded matches were normal” in the 1980s and that “sometimes life is unfair and accidents happen”.

I understand that people have the need to blame others, the cover up was wrong but in overcrowded stadiums accidents happened. https://t.co/T83CnCDzvu — Arron Banks (@Arron_banks) February 14, 2017

I didn't say there wasn't a cover up. Someone screwed up but it's still an accident and it's time to see it for what it is . https://t.co/nwEAIqT0wj — Arron Banks (@Arron_banks) February 14, 2017

Banks, who has more than 18,000 Twitter followers, was a key figure in the campaign to leave the EU, running the Leave.EU campaign that built a large social media following and sometimes infuriated the main Vote Leave campaign. He recently launched a provocative rightwing political news website, Westmonster.

Meanwhile, the revelation that Nuttall had not lost close friends at Hillsborough prompted an angry reaction from relatives of those who died. Margaret Aspinall, the chair of the Hillsborough Family Support Group – and whose 18-year-old son, James, died in the disaster – described the admission as “appalling”.

She had previously questioned why Nuttall had never offered to support the families’ campaign to challenge the police cover-up and to win justice.

It also prompted a number of MPs to denounce Nuttall, with Tim Farron, the Liberal Democrat leader, saying: “It is sad to see a tragic event like Hillsborough being dragged into politics in this way. Paul Nuttall’s blatant untruths have caught up with him. I’m sure voters in Stoke will punish him as a result.”

Nuttall is aiming to become Ukip’s second MP by winning the byelection for Stoke-on-Trent Central on 23 February. It was triggered by the decision of the Labour MP Tristram Hunt to step down from the Commons to become director of the Victoria and Albert Museum.

More than two-thirds of Stoke voters backed Brexit in the referendum last June – one of the most decisive margins in the country.

