LONDON: Manchester United supporters opposed to the flotation of the English soccer club in New York called on Friday for a boycott of sponsors' products to put pressure on the Glazer family to ditch the plan.

The call risks embarrassing the club just days after it signed a record-breaking shirt sponsorship deal with U.S. auto company General Motors.

"The boycott strategy is intended to send a loud and clear message to the Glazer family and club sponsors that without the support and purchasing power of the fans - the global strength of the Manchester United brand doesn't actually exist," the Manchester United Supporters Trust (MUST) said in a statement

MUST has accused the American Glazers of hurting the team's performance by saddling it with debt in a 790 million pound ($1.23 billion) takeover in 2005.

It has also been angered after the Glazers said they would raise up to $167 million themselves in the flotation after initially saying all the proceeds would be used to cut the debt.

"It is hoped sponsors will put pressure on the Glazer family to reconsider their plans," MUST added.

United have more than 70 commercial partners around the world.

MUST, which campaigns for greater fan involvement in the ownership of English soccer's most successful club, has around 180,000 members and has fought a high-profile campaign against the Glazers.

However, a recent survey commissioned by the club estimated it had 659 million global followers - almost one in 10 of the population.

The power of its brand was illustrated this week when it agreed the deal with General Motors to have the Chevrolet name on its famous red shirts from 2014. The agreement was reportedly valued at $60-70 million per year.

GM declined to comment on the boycott call.