The developer who holds the record for the most expensive property deal ever in Ireland has been given just one working day to come up with almost a billion dollars by NAMA.

The National Asset Management Agency, set up by the Irish government to recover bank debt from developers, has ordered Ray Grehan to stump up the cash by close of business on Tuesday.

Grehan and his brother Danny successfully applied to NAMA to have their Glenkerrin Group taken out of receivership after a shock move by the state agency on Wednesday.

NAMA granted the appeal when it stood the receivers down on Saturday but the move is only temporary.

Now NAMA has confirmed that the Grehans will have to repay their full €660 million worth of loans by Tuesday night – and they only have until Tuesday because Ireland Inc is closed down for a bank holiday on Monday.

The Grehan brothers hit the headlines in 2005 when they paid €171.5 million for the site of the former UCD veterinary college in Dublin’s exclusive Ballsbridge neighbourhood.

That deal valued the Dublin 4 site at €82million per acre, an Irish property record that is unlikely to ever be broken.

The receivers moved on the developers’ Irish loans on Wednesday. These loans include deals on the UCD site, the Glenroyal hotel in Maynooth and various apartments and offices at the Grange in Stillorgan.

The brothers, in talks with the agency since last December, had asked for more time to respond to the NAMA decision and make arrangements to broker a deal and they now have until Tuesday to come up with the cash.

A spokesman for NAMA told the Sunday Independent that the decision to withdraw the receiver was: ‘based on legal advice and made in response to a request from the Grehan brothers for additional time to negotiate the repayment of their loans.'

The spokesman also insisted that demand letters for the immediate repayment of the Grehans’ entire €660m debt would be re-issued on Tuesday evening.

The receiver will be re-appointed to the Glenkerrin group if the debt is not settled at the close of business on Tuesday.