British officials held emergency talks in Brussels yesterday to hammer out stronger guarantees that the new EU treaty will not give European judges the right to challenge foreign policy.

The meeting will be followed by another on the legal details today, in a sign that the Government is nervous about the impact of the proposed treaty, despite repeated assurances that it will not leave diplomacy open to challenge in the European Court of Justice.

British officials hope to agree new wording by Friday to make it “crystal-clear” that the treaty, which is replacing the failed EU constitution, cannot be used in Europe’s highest court in Luxembourg by pressure groups or anyone else to challenge foreign policy decisions.

Publicly David Miliband, the Foreign Secretary, has consistently said that he is content with the outline agreement of the new treaty that was reached in Brussels in June.

He insisted that there was no need for the referendum promised by Tony Blair on the EU constitution because this was a different style of treaty that did not threaten British sovereignty. But behind the scenes officials were pressing for greater assurances.

The first draft of the treaty text was said to have alarmed British negotiators because it suggested that international agreements made under the EU’s common foreign and security policy could be open to challenge in the courts. They saw this as a watering down of a key “red-line” demand that Britain retains full control of its foreign policy decisions with no possible chance of EU judges overruling them.

British officials realised that without an immediate strong challenge public confidence in the new treaty could be further undermined, just when ministers are coming under increasing pressure to hold a referendum.

After calls for a referendum, officials hope to have a declaration in Brussels by Friday that the treaty will not leave foreign policy open to legal challenge. One EU source said: “What the British want is an over-arching clause that states that the European Court of Justice has no jurisdiction over common foreign and security policy.”

Europolitics, a Brussels-based newsletter, reported yesterday: “Gordon Brown’s Government has demanded clarification on the place of foreign policy and common security policy in the future treaty, asking for guarantees about the independence of British diplomacy, particularly concerning the authority of the European Court of Justice in this area.”

A government spokesman in Brussels insisted that the bilateral talks between British and European Commission lawyers were part of the normal process of negotiating the fine print of a treaty. He said: “We secured all of our red lines in June. Lawyers are now turning that agreement into a treaty text and the UK will ensure that all its red lines are fully respected.”

The new treaty is designed to replace the EU constitution that was rejected in referendums in France and the Netherlands in 2005. It contains many of the reforms envisaged in the constitution, however, such as creating an EU foreign minister. It will also reduce the number of commissioners and create a powerful role of full-time president of the European Council to co-ordinate the 27 members. National vetoes will be scrapped over decision-making in a series of justice and criminal policy areas but Britain has won the right to opt out of new measures agreed by qualified-majority voting.

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