Standing with the visiting French President, Jacques Chirac, the Prime Minister said no head of a nuclear state could have ignored scientific advice that testing was needed to ensure a safe and reliable deterrent. "On that basis I have offered the President my support," said Mr Major.
The British Government sent a clear message from the Anglo-French summit that it intends to ride out the storm of protest against the tests from Commonwealth nations in the interests of what Mr Major and Mr Chirac christened their "global partnership".
Issuing a statement redolent of the old entente cordiale, they declared: "We do not see situations arising in which the vital interests of either France or the United Kingdom could be threatened without the vital interests of the other also being threatened."
The secretive Joint Nuclear Commission, which brings together British and French experts, will meet to determine ways of strengthening nuclear co-operation.
Mr Chirac, while fulsome in his praise of the British Government, denied that these enhanced ties between London and Paris diminished the importance of the link between France and Germany, which he described as "a friendship - not an axis".
Mr Chirac said he found a refreshing change in the tone of Anglo-French exchanges since he last participated in such discussions - which was during the premiership of Margaret Thatcher. "One no longer hears phrases of ill-humour and aggressiveness," said Mr Chirac.
The French President made it clear, however, that Britain and France retained different views on the future of Europe. Mr Chirac said France was committed to monetary union but said Britain's right to opt out would be respected.
In a sign that some discreet haggling has taken place over the new Secretary General of Nato, both Mr Major and Mr Chirac said they would strongly support the former Dutch Prime Minister, Ruud Lubbers, if he became an official candidate, putting an end to speculation that a British contender might come forward to succeed Willy Claes of Belgium.
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