Senior Iranian lawmakers rejected on Saturday a U.N.-backed plan to ship much of the country's uranium abroad for further enrichment, raising further doubts about the likelihood Tehran will finally approve the deal.

The U.N.-brokered plan requires Iran to send 1.2 tons of low-enriched uranium — around 70 percent 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.

Iran has 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.

The Tehran reactor needs uranium enriched to about 20 percent, higher than the 3.5 percent-enriched uranium Iran is producing for a nuclear power plant it plans to build in southwestern Iran. Enriching uranium to even higher levels can produce weapons-grade materials.

"We are totally opposed to the proposal to send 3.5 percent enriched uranium in return for 20 percent enriched fuel," senior lawmaker Alaeddin Boroujerdi was quoted by the semiofficial ISNA news agency as saying.

Boroujerdi, who heads the parliament's National Security Committee, said the priority for Iran was to buy nuclear fuel and hold on to its own uranium. He also said there was no guarantee that Russia or France will keep to the deal and supply nuclear fuel to Iran if Tehran ships them its enriched uranium.

"The preferred option is to buy fuel ... there is no guarantee that they will give us fuel ... in return for enriched uranium. We can't trust the West," ISNA quoted Boroujerdi as saying.

Kazem Jalali, another senior lawmaker, said Iran wants nuclear fuel first before agreeing to ship its enriched uranium stocks to Russia and France even if it decides to strike a deal.

"They need to deliver nuclear fuel to Iran first ... the West is not trustworthy," the official IRNA news agency quoted him as saying.

Jalali said Iran needs fuel and putting conditions to deliver it for the research reactor is unacceptable.

"Countries possessing fuel are required, under international rules, to provide fuel for such reactors. Putting conditions is basically wrong," he said.

Jalali said these conditions for the fuel was teaching Iran new lessons.

"Western approach toward Iran's demand for fuel is only straightening Iran's resolve to continue its peaceful nuclear program," he added.

The lawmaker said France has reneged on previous agreements and that Tehran doesn't trust Paris.

He said Iran holds a 10 percent share in a Eurodif nuclear plant in France purchased more then three decades earlier but is not allowed to get a gram of the uranium it produces as an example that Iran can't trust the West.

Tehran says it has paid for 50 tons of UF-6 gas, which can be turned into enriched uranium, in Eurodif's plant but has not been allowed to use it.

"Iran is a shareholder in Eurodif but doesn't enjoy its rights. This shows the French are not reliable," Jalali said.

Areva, the state-run French nuclear company, has described Iran as a "sleeping partner" in Eurodif.

The U.S. and its allies have been pushing the U.N.-backed agreement as a way to ease their concerns that Iran is using its nuclear program as a way to covertly develop weapons capability.