David Heathcoat-Amory, Shadow Chief Secretary to the Treasury, made the allegation in a letter to Tony Blair in which he asked the Premier whether he could "continue to have in your Government a minister who clearly and persistently breaches the established rules on declarable interests".
The Tories claim that Mr Robinson was chairman of a Swiss company subsidiary, Agie UK Ltd, for several years from 1984 but did not declare his earnings until 1987.
In a separate letter to the Postmaster-General, Mr Heathcoat-Amory said: "The rules of the House made clear such a declarable interest had to be recorded within four weeks. You omitted to declare your interest in Agie for at least three years.
"Since you were at the time a Labour front-bench spokesman for trade and industry matters, a correct declaration was even more important."
The Tories claim that Mr Robinson was paid a total of more than pounds 100,000 as chairman and that he was the highest-paid director of Agie UK Ltd prior to the first disclosure of his remuneration in the register of MPs' interests published in December 1987.
Mr Heathcoat-Amory has also submitted details of the alleged breach of rules to Sir Gordon Downey, the Parliamentary Commissioner for Standards, asking him what action he will recommend.
Mr Robinson's political life has been under a cloud since revelations in the Independent on Sunday that he was a beneficiary of a substantial offshore trust based in Jersey.
A spokesman for the Paymaster-General last night dismissed the latest allegations as "another pathetic attempt to smear Geoffrey Robinson".
He added: "He has registered his interests and clearly has nothing to hide."Reuse content