TransTec, the engineering company in which former Treasury Minister Geoffrey Robinson is a major shareholder, has called in the receivers.

In a statement, Transtec said it has invited its lenders to appoint receivers to the company.

"Accordingly, HSBC, on behalf of the lenders, has appointed John Talbot, Murdoch McKillop and David Duggins of Arthur Andersen as joint administrative receivers for TransTec," it said.

The company's board of directors took the action after failing to secure backing from its bankers for an orderly sale of its trading assets.

The company admitted its financial difficulty just before Christmas, when its shares were suspended after the discovery of accounting irregularities.

The chief executive and finance director have both resigned, after disclosing that the company had an undisclosed claim for $18m (£11m) from its largest customer, the Ford Motor Company.

Mr Robinson, who resigned from the government last year over a £373,000 personal loan he made to Peter Mandelson, founded TransTec in 1981.

Under his leadership it became a major engineering group in the motoring industry. But recently, the company has been struggling, with high debts and sales hurt by the high pound.

Despite selling its measurement business for £32m, the company still had debts of £66m in June 1999.

Mr Robinson owns around 30 million shares which at their peak were worth around £1.20, but had slipped to 6.5p by 24 December - making them now worth around £1.9m rather than £36m.

He resigned as chairman of the company in May 1997, after he entered the Labour government.

However it is still unclear whether he was aware of the undisclosed claim, which was reportedly made sometime between the end of 1996 and late 1997.

The company says it settled two-thirds of the claim in 1998, but that $6m (£4m) is still outstanding. Further investigation

Meanwhile, Conservatives have been calling for a further Department of Trade and Industry inquiry into the affairs of Transtec.

His role was defended was the chairman of his constituency association, William Thomson.

"They keep investigating Geoffrey and finding nothing at all .. he is basically a very honest man," he said. .

The demand comes just days after the Department of Trade and Industry cleared the one-time paymaster general of any wrongdoing in his other business dealings.

Trade Secretary Stephen Byers said no further action would be taken following the inquiry into Hollis Industries, one of the companies closely associated with the Coventry North West MP.

Mr Robinson, a self-made millionaire, was accused by the Tories of stripping assets from Hollis Industries just before it went into liquidation, leaving little left for the creditors.

Mr Robinson's memoirs are eagerly anticipated by the media following speculation over what revelations it may contain.