The owner of The Peel Group - the company behind Gloucester Quays - has seen his personal fortune fall by £350million in the last year amid growing concerns about the future of one of his prime assets.

According to the annual Sunday Times Rich List, which was released yesterday, John Whittaker's worth fell to £1.6billion.

Peel opened the Quays outlet and leisure area in 2009 and invested in the area as part of a portfolio which also includes Media City at Salford Quays, home of the BBC, and Liverpool John Lennon Airport.

Peel is based at its landmark development The Trafford Centre in Manchester, which it sold to Capital Shopping Centres - now Intu Properties - in 2011 for £1.6billion in the biggest property acquisition in Britain.

Mr Whittaker retained a near 25 per cent stake in Intu which has fallen from a place in the FTSE 100 to heavy debts - place at £4.5billion in March - which have been exacerbated during the coronavirus pandemic

Intu has announced today that it is seeking standstill agreements from its lenders as it looks to offset a collapse in rent income.

At the start of the month, Intu said it had collected 40 per cent of rent due from retailers hit by closures during the coronavirus pandemic.

A statement said: "There can be no certainty as to whether any standstill can be achieved with all or some of the group's creditors, or as to the terms.

"While the standstill is the primary focus, it is possible that earlier individual breaches, under certain of the group's financings, could occur over the coming weeks and the group will see to address such instances as part of the wider discussions."

Peel raised more than £1billion by selling stakes in Liverpool airport, Peel Ports and developer Harworth.

Gloucester Quays has become a major part of the city's economy and daily life after Peel's support helped it overcome a slow start following the financial crisis.

As well as the outlet mall and leisure complex featuring bars, restaurants and Cineworld, the Quays - which celebrated its 10th birthday last year hosts regular events throughout the year.

The annual Christmas Market, ice rink, Food Festival, monthly food market and the Tall Ships have attracted tens of thousands of visitors over the past decade.

The Quays is currently closed due to the Government's coronavirus restrictions.