Manchester United supporters are mulling a boycott of club sponsors as a way to oust the club's owners - the Glazer family.

The ill-feeling towards the Glazers has existed since their takeover in 2005, and has reached new heights after the club's erroneous decision to join the European Super League.

A significant contingent of fans protested pre-match ahead of the team's Premier League game with Liverpool on Sunday.

Some fans even made it inside Old Trafford before the game, leading to a postponement of the match.

"Your sponsorship money will be used for debt servicing and dividends. Supporting the Glazers does not support the club. It sustains a parasitical relationship," an open letter from a group of Manchester United fans read.

"The Glazers engorge on commercial revenue, you exploit the fanbase to access global markets, and fans are left desperate as the club weighed down by debt is unable to marshal its own resources to compete where it should. Supporting the Glazers is therefore an attack on Manchester United Football Club.

"To that end, Manchester United fans will boycott your products, seek to tarnish your brands and support your competitors until you terminate your commercial partnership with the Glazer family.

"United fans have sought every possible avenue since the takeover to improve the situation: from peaceful protesting and open letters, to fan-led share purchase initiatives and consortium bids.

"The Glazers have ignored every attempt. Even after promising to 'rebuild trust with fans', Joel Glazer declined to participate in a Fans Forum last week. Desperate, we have been left with no other alternative but to attack what the Glazer family are reliant on: commercial revenue and brand reputation.

"Until then, if you are complicit with the Glazers, you are complicit in the attack of Manchester United Football Club as well as the attempted murder of English football."