In a move not seen for a decade, the Select Committee on Foreign Affairs issued a special report asking the House of Commons to adjudicate on the row.
The committee also plans to recall Sir John Kerr, permanent secretary at the Foreign and Commonwealth Office, who appeared before it last week. Later, he was forced to retract a claim that Tony Lloyd, a Foreign Office minister, had been fully briefed on the affair.
Last night's developments will have caused further anguish to Mr Cook, who had been hoping that the row over Britain's apparent collusion in the reinstatement of President Ahmad Tejan Kabbah would die down. Earlier this week, an independent inquiry was launched after Customs and Excise announced that it would not prosecute Sandline International, the British firm which supplied arms to Sierra Leone, apparently in breach of a United Nations embargo but for which the company claimed it had Foreign Office approval.
Mr Cook refused to hand over the series of telegrams last week, saying they contained sensitive material. The committee voted to publish its instant report yesterday despite the opposition of its chairman, Donald Anderson. The move amounts to a demand that the House of Commons should debate the issue.
Diane Abbott, Labour MP for Hackney North and Stoke Newington, voted with four Conservatives and one Liberal Democrat to defeat opposition from her own party by six votes to four.
Last night, Ms Abbott said the report could become a test of strength for the committee system. If the Government did not allow a full debate on the report then the rules of the house would have to be changed, she said. As committees were not whipped, she did not expect to be disciplined. "Select committees are supposed to have the power to call for persons and papers, and it is not a power that has ever really been tested. This is the first time we have done it and the Foreign Office has refused. I think we need to pursue it further," she said.
David Wilshire, Conservative MP for Spelthorne, said: "The majority of the committee feel very strongly indeed that they should be given the whole story. It is a matter of principle: do we just lie down and allow the Government to trample all over us, or do we take a stand?"
David Heath, the Liberal Democrat member for Somerton and Frome, said he was "very unhappy" about Mr Cook's refusal to hand over the telegrams. "Clearly there is scope for a compromise but we do need to know," he said.
Answering questions in the Commons on the issue, the Leader of the House, Ann Taylor, said that Mr Cook was acting within his rights.
"When Robin Cook wrote to the select committee he did say that it was the ministerial practice of any party in government that telegrams should not be made public ... other governments and individuals expect their confidences to be respected," she said.Reuse content