The foreign secretary has signalled that a conflict with Iraq would not postpone any referendum on the euro.

Jack Straw said that "extraneous issues" would not hamper the government's long planned euro assessment.

"Is the timing of any referendum on the euro dependent on a 'big if' about military action in Iraq? Well, no," Straw told the FT.

The claim came amid high level fears that a war with Iraq would blow apart the prime minister's plan to hold a referendum as early as next spring.

He said that the Cabinet "will recommend that we join" once the five tests have been met.

Straw, a late convert to the single currency, said it would be wrong to allow wider international issues to undermine the government's euro plans.

He told the newspaper: "That being so, by what process would we suddenly say: 'Well, by the way, we've decided we're not to keep to this rubric about the euro, instead we will allow extraneous issues to come in'?

"So, you know, that work is proceeding. And if the overall judgment on that is that the five tests are met, there is convergence, then cabinet will recommend that we join."

Straw said that the government had already given a commitment to complete the chancellor's critical five tests for entry by early June next year.

The foreign secretary also used the interview to stress that securing weapons inspections in Iraq remained the central policy of the government.

"The weapons inspectors did find a good deal of material...They have now said that they are willing to talk about the reintroduction of weapons inspectors, but as usual they are playing games. But we have to put them on the spot."