Gary Neville has opened fire on the Glazers are demanded they sell up at Manchester United with the American owners presiding over consistent failure at Old Trafford

Gary Neville has again called for the Glazers to sell up at Manchester United as he doubled down on the astronomical debt they've amassed and their refusal to take responsibility for their shortcomings.

For two decades the Glazer family has sat at the top of the club and the flaws in their ownership were masked for a period by the success enjoyed under Sir Alex Ferguson, but since his retirement the Red Devils have endured a steep decline.

A lack of achievement on the pitch has shone a light on the issues in the boardroom and Neville, a former captain of the club, has continued to speak out against the American owners, who are rarely if ever seen at the club.

For long periods they delegated to other figures, who became hugely unpopular among fans, and in recent years sold a stake to INEOS, who are now copping it from the supporters. But Neville maintains that the overall issue remains with the Glazers.

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He said on Stick to Football: "There's £1.2 billion ($1.6 billion) of debt in that football club, they're hamstrung in some ways. They've spent an absolute fortune on players, just under Man City in the last 15 years. £1.4bn ($1.86bn) on players, they're second in the spending, but a lot of it's the never-never.

"They have to sell now, they have to sell, I'm sorry the time has come. They have subcontracted the football department out to INEOS, they are trying to run the football department, they have had three years of struggling and it looks like this year is going to be a struggle.

"The Glazer family over in America, in Tampa, they're very popular over there, they go to every game, apparently, I hear, they go to all the NFL games, they've hardly been to Old Trafford in 20-odd years."

Neville went on to lament their failure to invest in Old Trafford, which has fallen way behind the elite stadiums in the world today. Plans are being made for a new venue, but the former player questioned where the apparent £2bn to fund it is going to come from.

He concluded: "You've got a failure of 13, 14 years on the football side, you've subbed it out to somebody else, which is ridiculous, and not took responsibility. It is now at a point where they have to sell. Enough is enough, they have to sell the whole the club. The fans have had enough. They have to go now."

Neville has previously confessed to a sense of regret at not speaking out against the Glazers when he was a player at the club, but has said: "I worked on the theory at the time that we could have worse owners. They were quite passive.

"But when Sir Alex Ferguson left, it's then I started to realise they were only successful because of Sir Alex Ferguson. They haven't been able to develop a successful sporting project without him."