Explaining in detail for the first time his own role in the extraordinary saga, he said that as foreign secretary he would not have expected to have been told but that the then home secretary, Michael Howard, the attorney general, Sir Nicholas Lyell, and possibly the prime minister, John Major, should have been.
Mr Rifkind gave the go-ahead in 1996 to publish the material brought to Britain by the defecting KGB archivist, Vasili Mitrokhin, but insisted that MI6 had not drawn his attention to the revelations about Mrs Norwood.
He shared the concern that MI5 had unilaterally taken the decision not to prosecute Mrs Norwood rather than consult ministers. The onus was now on MI6 and MI5 to provide a satisfactory explanation of their actions.
He said yesterday: "If they can provide a convincing explanation, a satisfactory one, then clearly there will be no need for concern. But the onus will have to be on them to provide that explanation because... if information is obtained by anyone that points to the identity of a Soviet spy who operated in the United Kingdom, that is information that, on the face of it, should have been made available to the relevant ministers."
Mr Major, Mr Howard and Sir Nicholas appear not to have been told.
Although the interest has been in Mrs Norwood, the bulk of the material brought in by Mr Mitrokhin - six trunks full - was not about individuals but about KGB policy in broad terms since 1917, he said.
"It was that breadth of information which explains why it took four years between 1992 and 1996 for the information to be analysed and scrutinised and it was at the end of that stage, the analysis having been completed, [that] the recommendation came to me as foreign secretary that... a lot of this material, there was no reason for it to be kept classified or confidential."
