To anyone who followed the course of the negotiations of the Nuclear Non-Proliferation Treaty in New York earlier this year it is inconceivable that the non-nuclear countries would have signed an indefinite extension of the treaty had they known what the French planned. The resumption of the French nuclear programme flies in the face of progress towards a Comprehensive Test Ban Treaty. To agree to such a treaty only when your nuclear programme has been completed will seem to some to make a mockery of the whole process.
Carson Mark, the former head of the theoretical division of the Los Alamos laboratory in the United States, is on record as saying that "the reliability, effectiveness, safety and security of our nuclear arsenal can be maintained without nuclear tests". Any further testing should therefore be carried out in laboratories, and Britain should offer any results that we have from such tests to the French. Genuine co-operation of this kind could well be instrumental in persuading the French to cut short their testing programme.
The Conservative government's refusal to condemn the renewal of French testing is unforgivable. Conservative ministers should be using every endeavour to persuade the French not to proceed. Yet they have refused to intervene.
In contrast, more than 150 governments have called for an immediate halt to the French tests. Britain stands out for its refusal to follow suit. The Conservative line that "it is a matter for the French government" does not ring true.
This is a matter for every government committed to a world where nations work together to preserve peace and protect the environment. Everyone who wants a future free from the dangers of nuclear proliferation must put pressure on the Conservative government to intervene. The two countries engage in regular dialogue about their nuclear deterrents. The influence Britain has may be what it takes to make President Chirac back down.
Liberal Democrats have been campaigning on this issue since the French first announced this decision. Robin Teverson and Graham Watson were the only MEPs to boycott Mr Chirac's speech to the European Parliament in July, and Matthew Taylor, our environment spokesman, was the first to raise the issue in Parliament. We will continue to pressure the French and British governments until these tests are halted.
The writer is the Liberal Democrats' defence and foreign affairs spokesman.