The Australian Greens are demanding the Gillard government explain whether it privately supports uranium sales to India.

Leaked WikiLeaks cables reveal Resources Minister Martin Ferguson told US officials in 2009 a deal to supply India with nuclear fuel could be reached within years.

The stance contradicts the government's public position of insisting that India sign up to the Nuclear Non-Proliferation Treaty before being allowed to import Australian uranium.

Greens nuclear spokesman Scott Ludlum says it appears the government is playing a "double game".

"I swear some days you can smell the uranium on Martin Ferguson's breath," he told reporters in Canberra on Thursday.