Middleton is considered a science success

Assembly Finance Minister Sue Essex has given the site - now known as Middleton - a temporary lifeline to keep it open for another month.

But trustees say the undisclosed amount is not enough.

Alan Heyward, chair of the garden's board of trustees, said: "The amount of money they have offered is inadequate.

"The conditions attached to the offer are commercially, legally and financially unacceptable to the trustees."

The garden - which was part-funded with lottery money - has consistently failed to hit its financial and visitor targets.

The offer has been made in the hope the garden's trustees could find long-term business partners to bail out the business.

Ms Essex did not reveal the exact amount offered, but revealed that winter running costs were in the region of �230,000.

She did not rule out further cash support for the garden, but added that the assembly government still viewed Middleton as a visitor attraction, and not in the same category as the National Museums of Wales.

Mr Heyward said not enough was being done to help the gardens.

"The Welsh Assembly Government wants to extend the garden's life for a month so they can possibly find partners," he said.

"If they fail to find the partner, the money they gave us to help to pay the operating costs of the garden is to be repaid personally by the trustees back to the Welsh Assembly Government.

"So you can see - this puts the trustees in an absolutely impossible position."

He added the trustees had had a "Plan B" for the garden, but it would have had to have been implemented in June, when the funding ran out.

"They have made the decision far to late," he said.

But the First Minister's office said Mr Heyward's statement was incorrect and the assembly government would have "no legal recourse to seek re-payment of the grant".

The Culture Minister, Alun Pugh, has come in for fierce criticism by opposition parties in the Assembly for his handling of the financial crisis.

The money will keep Middleton's gates open for another month

Plaid Cymru AM, Rhodri Glyn Thomas, said it was "irresponsible to pull the plug" on the gardens and claimed the Assembly Government had failed to spell out its attitudes to further funding to the directors.

The extra funding comes less than a day after First Minister Rhodri Morgan had dismissed the possibility the assembly bailing out Middleton.

Trustees of the �43m gardens site at Llanarthne, Carmarthenshire, west Wales, had sought a further �300,000 to see them through the financial year or else face calling in the receivers.

The garden - opened in May 2000 by Prince Charles - has already had �1.4m of assembly cash this year to ease its costs and fund a marketing drive.

It is understood garden trustees will consider assembly's offer at a meeting on Thursday.

Speaking on Monday, Mr Morgan had said there could be no question of taxpayer's cash being used to keep Middleton's doors open.

One hundred jobs at the garden hang in the balance.