Opposition MPs were left fuming after controversial Paymaster General Geoffrey Robinson offered a "derisory" apology to the Commons for breaching parliamentary rules on his share ownerships.

BBC's John Sergeant: "The statement lasted less than a minute"

Both the Tories and the Liberal Democrats demanded his sacking after he made a personal statement of less than a minute in which he insisted he had not benefited commercially from the "oversight".

He added to the anger by saying he had now amended the MPs' register of interests to include the directorships, and had included another company that was not even referred to in the critical report.

Geoffrey Robinson's statement to the House of Commons

The brevity of his statement shocked even some on his own benches and led to Tory claims he had failed to show proper respect to the Commons.

The minister should go, says David Heathcoat-Amory

Shadow Treasury Secretary David Heathcoat-Amory said his addition of another directorship meant he was asking for an extra offence to be "taken into account."

Now closed

But Prime Minister Tony Blair is still standing beside his minister and insisting the matter is now closed.

The row erupted after Mr Robinson was criticised for the third time by the powerful standards committee of MPs, which has previously cleared him of more serious offences.

They said he had broken the rules by failing to register shareholdings and ordered him to apologise to the Commons.

The Labour chairman, Robert Sheldon, underlined the seriousness of the matter, stating: "The committee has taken the view that failure to register is an important matter, even though he says he received no benefit from failing to register."

BBC Political Correspondent Jon Devitt: "It is extremely embarrassing for the prime minister"

But Mr Blair resisted Tory demands for him to be sacked and spokesmen suggested the punishment of having to make a full public apology in the Commons chamber was humiliation enough.

But the one-minute statement failed to answer his critics and only added to the demands for his head.

He told MPs: "No attempt was made by me at any time to use my position in this House to advance any commercial interest."

Brief words

He added: "The oversight concerning registration, for which I apologise, is entirely my responsibility."

But Mr Heathcoat-Amory said the paymaster general "cannot expect to get away with a few brief words of apology to the Commons.

"Even his statement added yet another twist to his complex business dealings. It is not clear why he referred to his involvement in Roll Centre Inc, a company which is not even mentioned in the report.

"The time for apologies passed long ago. It is time to bring this sorry affair to an end. Nothing less than his resignation will do."

He said his statement had been "derisory and minimal".

He added: "He was just going through the motions. He clearly thinks these are boring, trivial little breaches. But they are building up into a pattern - this man just breaks the rules."

And Liberal Democrat spokesman Malcolm Bruce added his voice to the demands, saying: "With regret, I believe that Mr Robinson's credibility at the Treasury has now been seriously undermined and it is time for him to consider resignation."

Earlier, Mr Blair had brushed aside demands for Mr Robinson's resignation, saying: "As the minister has already pointed out this refers to a time before he was a minister, he accepts it was an oversight on his behalf and I think the House should listen carefully to what he has to say."

But the pressure on Mr Robinson is now intense with even the government's "partners" in the Liberal Democrats turning their back on him.

Some in Labour believe that taking a businessman with such complex dealings into the cabinet was a recipe for trouble.