Senior Iranian lawmakers rejected on Saturday any possibility of Tehran shipping uranium abroad for further enrichment, intensifying pressures on the government to reject the UN-backed plan altogether.

Prominent conservative lawmaker Alaeddin Boroujerdi said Iran won’t ship its low enriched uranium abroad in a single batch or in several shipments, a compromise suggested by some government officials, under any circumstances.

“Nothing will be given of the 1,200 kg (of low enriched uranium)... to the other side in exchange for 20 per cent enriched fuel, not in one batch nor in several. It is out of question,” semi-official ISNA news agency quoted Boroujerdi as saying on Saturday.

The UN-brokered plan required Iran to send 1.2 tonnes of low-enriched uranium — around 70 per cent of its stockpile — to Russia in one batch by the end of the year, easing concerns the material would be used for a bomb.

After further enrichment in Russia, France would convert the uranium into fuel rods that would be returned to Iran for use in a reactor in Tehran that produces medical isotopes. Fuel rods cannot be further enriched into weapons-grade material.

Earlier, Iran had indicated that it may agree to send only “part” of its stockpile in several shipments. Should the talks fail to help Iran obtain the fuel from abroad, Iran has threatened to enrich uranium to the higher level needed to power the research reactor itself domestically.

On Saturday, Russian President Dmitry Medvedev signaled that Moscow could back sanctions against Iran if it fails to take a constructive stance in international talks over its nuclear programme. He told the German magazine Der Spiegel that it would be better to avoid sanctions, but they can’t be excluded if there is no progress in the talks.