Spencer Hart has gone into liquidation after racking up £1.25m in debts

Ed Miliband's favourite Savile Row tailor has gone bust – costing a string of celebrity investors hundreds of thousands of pounds.

Spencer Hart, the design label which made the suit Mr Miliband wore to address the Labour conference last week, has gone into liquidation after racking up debts of more than £1.25 million.

TV stars James Corden, Ant and Dec and Dermot O’Leary as well as singer Robbie Williams are among those left out of pocket by the collapse.

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Star backing: Robbie Williams, left, who ploughed £250,000 into Spencer Hart retail, set up by Nick Hart, right

Suits from Spencer Hart Retail Ltd featured in Sherlock Holmes, starring Benedict Cumberbatch

Companies House records show that Williams invested the most, ploughing £250,000 into Spencer Hart Retail Ltd, while Corden put in £73,500.

X Factor host Dermot O’Leary contributed £49,000 and Ant McPartlin and Dec Donnelly handed over £90,000 each.

The firm was set up by designer Nick Hart in 2002, and named after his son.

It quickly became a favourite among celebrities, counting Daniel Craig and David Bowie as customers; while Benedict Cumberbatch modelled the brand in a Spencer Hart catwalk show in 2012.

Mr Miliband also wore Spencer Hart for his keynote speech at last year’s party conference.

The company’s financial woes came to light last year when it was forced to enter into a company voluntary arrangement (CVA), which allows insolvent or debt-ridden firms to keep trading to settle their bills.

Benedict Cumberbatch is often seen wearing one of Spencer Hart's trademark suits

Chic: Benedict Cumberbatch with a model showcasing the brand on the Spencer Hart catwalk in 2012

Last night Mr Rubin told The Mail on Sunday that creditors were ‘concerned’ by the liquidation.

Spencer Hart agreed to repay creditors at a rate of just under £2,000 a week over a five-year period.

But documents reveal that, after Mr Hart failed to raise extra funds to rescue the business, he was forced to appoint a team of accountants to wind it up in June.

This means celebrity backers have little chance of getting back their investments.

Hollywood star Matthew McConaughey, pictured with wife Camila Alves, dressed in a Spencer Hart suit for the 65th Cannes Film Festival post-screening party of 'The Paperboy'

James Corden, left, invested £73,500 in the company while X Factor host Dermot O’Leary, right, contributed £49,000. They are both pictured in a Spencer Hart suit

Accountancy firm David Rubin and Partners is currently investigating how the company managed to fall into so much debt and has begun contacting the high-profile investors to explain the situation.

If the report finds Mr Hart had been paying himself too much from the business, then the investors could sue him.

It is believed that the company’s flagship store – which opened opposite Claridge’s in Mayfair in 2011 – has been a hefty drain on resources.

The tailor became popular in celebrities circle, including among Daniel Radcliffe, left, and Sean Combs, right, the rapper also known as Diddy and Puff Daddy

British model David Gandy pictured left wearing Spencer Hart at a charity ball in London, while Alex Turner, frontman of the Arctic Monkeys, is pictured at the launch of the designer's flagship store in 2011

The company also has a second store in Savile Row. Between 2010 and 2012 alone, the company made pre-tax losses of £811,337.

A second company run by Nick Hart – Hart Savile Row Ltd – also filed a CVA with Companies House in February this year as it faced debts exceeding £250,000.

Robbie Williams invested after Hart provided the suits for his Swing When You’re Winning tour in 2002.