World powers could be ready to allow Iran to retain some of its uranium enrichment programme instead of demanding it be mothballed completely, diplomatic officials suggested last night.

Until now the UN Security Council has demanded that Iran stops enriching uranium over fears that it is a cover for mastering the means to build nuclear weapons.

Tehran, which faces two UN sanctions over the matter, says it seeks only nuclear-generated electricity but its concealment of sensitive enrichment research from the International Atomic Energy Agency and stonewalling of the agency's inquiries have shaken confidence in its intentions.

However, diplomatic officials yesterday said the US, Russia, China and key European powers may be willing to sidestep the deadlock by trying to agree a new way of defining enrichment.

The suggestion came on the eve of talks in Turkey between leading Iranian envoy Ali Larijani and Javier Solana, the EU's foreign policy chief.

A Foreign Office spokesman last night said he was unaware of the development.