Manchester United's Muslim Supporters' Club (MUMSC) has called for the Premier League side's co-owner to step down after he made "completely unacceptable" comments during a BBC interview.
Sir Jim Ratcliffe described the UK as being a country "on the slide" from the days when it had "the greatest empire in the world".
In what was described as a "statement of no confidence" posted on X, MUMSC said: "Our players, staff, stewards, security teams and supporters come from different countries, cultures, ethnicities, religions and backgrounds. Manchester United would not be Manchester United without them.
"Manchester United does not belong emotionally to investment funds, shareholders or billionaires.
"After years of decline, broken promises and repeated failure, Manchester United Muslim Supporters' Club has lost confidence in the current ownership structure of Manchester United Football Club.
"Enough is enough. It is time for change. The Glazers [co-owners] and Sir Jim Ratcliffe must go."
Ratcliffe, who founded petrochemicals giant Ineos and has resided in Monaco, which has a relaxed tax regime, since 2020, said Britain was in decline because of high taxes and immigration.
His latest attack on the UK comes seven months after he told Sky News that the country was being "colonised by immigrants". He subsequently said he was sorry if those remarks had "offended some people".
MUMSC said it had challenged those remarks earlier this year, adding: "We hoped a lesson had been learned. Clearly, it has not.
"This week, Sir Jim has again placed immigration and people receiving benefits at the centre of his explanation for Britain's problems, arguing that nobody is 'tough enough' to deal with either.
"We find these latest comments deeply disappointing and completely unacceptable."
The billionaire told BBC News's Big Boss Interview he believed the UK was in decline.
He said: "We had the greatest empire in the world. We were a great people. We won two world wars. We're good, honest folk.
"But unfortunately, at the moment, I think the UK is on the slide. It's quite difficult to see how we arrest it."
Ratcliffe also said the UK had "a bit of a green eye towards wealth at the moment", "encouraging" the wealthiest to relocate.
He told the podcast: "In America, they applaud people who create wealth.
"And the good thing about those people who create wealth is that they then spend that wealth in the economy in which they're resident.
"And, unfortunately, with the things that they've been doing, they've been encouraging the people who have created wealth to leave the UK because it's just become uncomfortable for them for tax reasons or whatever."
While the UK's tax burden has risen to its highest level since the second world war at about 35.3% of GDP, the Office for Budget Responsibility says it remains well below the average of 14 western European economies.
