In an apparent reference to the Left parties' opposition to the Indo-US nuclear deal, National Security Adviser M K Narayanan on Wednesday said the lack of consensus on the issue was hampering efforts to become a part of nuclear mainstream and needed an early resolution.

He said opposition to the nuclear deal within the country is driven by 'considerations' other than the factors like non-proliferation cited by some members of the international community.

He noted that India already has a close relationship with countries like Russia and France in the nuclear power sector and that the atomic deal with the US will open doors for commerce with the international community.

He said firming up the safeguards agreement with the IAEA and seeking waiver from the Nuclear Suppliers Group as part of the Indo-US atomic deal were essential steps towards entering the nuclear mainstream.

"Absence of a consensus within the country has been a major handicap (in seeking commerce with international community). It has put matters on hold and it needs a resolution earlier than later," Narayanan said.

He was obviously referring to the Left parties, whose opposition to the Indo-US nuclear deal has put the agreement on the back-burner.