William Hague, the Toryleader, said the Paymaster-General's position was "completely untenable" and he should step down. Mr Robinson was forced to make a personal apology to the House of Commons last week for failing to declare company directorships.
The inquiry involves a payment of pounds 200,000 which was said to have been made to Mr Robinson when he was chairman of Hollis Industries, a Robert Maxwell engineering company.
In July a House of Commons committee ruled that Mr Robinson had not received the money even though the firm's accounts noted the payment. But its report added: "This reflects poorly on the chairman, directors and others responsible for producing and approving Hollis's accounts and their accuracy."
Department of Trade and Industry officials are considering whether to take action over the apparent inaccuracies in the Hollis accounts, it was confirmed yesterday. The Conservatives released details from a letter from Peter Mandelson, the Secretary of State for Trade and Industry, to David Heathcoat-Amory, a Tory Treasury spokesman, written two months ago. The matter was under consideration but no further comment would be made, the letter said.
Mr Heathcoat-Amory also complained about a further 13 breaches dating from between 1988 and 1992. Most of them are minor but he believes they add up to a "disturbing" pattern.
The Standards and Privileges Committee has found Mr Robinson guilty of failing to declare interests in three companies. When apologising to the House last week, he took the opportunity to make amends for a fourth omission which had been highlighted by the Conservatives. An earlier report from the committee said he should have registered an interest in an offshore trust.
Speaking on BBC television's Breakfast with Frost, Mr Hague said Mr Robinson had tried to "shroud his affairs in secrecy" over a long period. "It is time for the Prime Minister to summon up his courage and say: `Out. There have been too many problems. You have been found guilty of too many things. It's time to be out of this government."
A friend of Mr Robinson said the minister had been the victim of dirty tactics.Reuse content