Following Friday's remarkable Financial Times report about early participation in economic and monetary union, which led to a stock exchange leap and a sterling slump, Mr Cook said yesterday: "There are some people in the press who think they know what we think better than we do."
Mr Brown was even more contemptuous. He told BBC television's Breakfast with Frost: "It's all nonsense, and I can tell you that these matters have not been discussed.
"Look, the position on Europe has not changed since we came into government; what we said in the manifesto is exactly what we are doing."
He repeated that it was most unlikely that Britain would participate in the first wave of single currency members, scheduled for 1 January 1999, but a later judgement on membership would be taken against a number of tests that mounted to "the patriotic interest".
"We think there are formidable obstacles to Emu entry. Of course, we see many advantages, such as cutting the cost of interest, cutting speculation, making business transactions easier; there are all the advantages of the single currency.
"What I did when we came into government was, I set five tests. Is it going to help jobs? Is it going to help investment in Britain? Is it going to help our financial services, the City of London on which a lot depends?
"Is the European economy flexible enough to withstand any shocks that might come if there was a single currency? Is the business cycle in harmony? These are the real questions that have got to be answered and we've got to make an assessment at the appropriate time.
Throwing his weight behind the Chancellor Mr Cook told the BBC radio World This Weekend programme: "We've always said that it's unlikely that we would join the first wave and there are formidable obstacles to us doing so."Reuse content