Robin Cook, the foreign secretary, has been told by the prime minister to moderate his policy of blocking arms sale to countries accused of serious human rights violations.

While Mr Cook yesterday outlined his plans for an ethical foreign policy to the Labour Party Conference, it emerged that aides of Tony Blair had reacted angrily to last week's announcement that three contracts worth £31 million had been blocked. [See The Guardian, 26 September. The licences were for arms sales to Indonesia.]

The prime minister's office wrote to Mr Cook, exppressing irritation at his handling of the announcement and asked to see all the documents relating to the decision.

Officials close to Mr Blair were understood to have been concerned about Mr Cook's public emphasis on the £31m, a tiny proportion of total arms exports. They stressed, however that the row had been patched up and that overall working relations remained good.

Trade union leaders, the companies affected, and the arms lobby as a whole had complained to officials about 'posturing', which, they said, damaged British weapons exports.

Courtaulds said it was baffled that its contract for six converted Land Rovers was blocked after they were classified as armoured personnel carriers. The other contracts related to sniper rifles.

Mr Cook's attempt to set a different tone has encountered hostility in Whitehall, although the project is proving popular among party activists.

Mr Cook said (in his speech to the Conference) Britain was giving 'a new lead on human rights' around the world. He referred to support from Mr Jospin, the French prime minister, for his proposed European Code of Conduct to regulate the arms trade.

However, Mr Cook said: 'Britain has one of the largest arms industries in Europe. We have a duty to the 400,000 people who work in our defence industries to continue to have the opportunity to work.'

Officials said that Mr Cook had felt under pressure to make a gesture ahead of the conference to affirm his commitment to ethics in foreign policy.

Non-governmental organisations and charities had been dismayed by a decision in July to let through contracts worth £3160 million for Hawk jets and other weapons to Indonesia, in spite of its human rights record in East Timor.

At the same time, the government published new criteria for arms sales that, while tighter than its predecessor's, appeared to have been toned down after fierce lobbying in Whitehall by the arms trade.

The defence industry believes the government is preparing to clear a backlog of licence applications pending closer scrutiny under the new rules.

Mr Cook is pinning hopes of change on a long-term shift in exports from defence. George Robertson, defence secretary, said the government is to publish a consultation paper on plans for a defebce diversification agency.

[Note: The Department of Trade and Industry wrote to Ann Clwyd MP on 3 October informing her that 'between 2 May and 25 September, eleven standard licences have been issued to end-users in Indonesia of good specified in Part 1 of Schedule III to the Export of Goods (Control) Order (1994) (the so-called 'Military List'); 4 such applications were refused.'

However the DTI would not divulge the equipment covered by the licences that had been granted. So, now we know that what Robin Cook told The Guardian on 26 September was only a tiny part of the truth. Far greater than the licences rejected, in number and certainly in value, were the licences granted - Tapol.]