Irked over Prime Minister Manmohan Singh [Images] 'belying' his assurance in Parliament on the Indo-US nuclear deal, the Left parties on Friday demanded a constitutional amendment to make it binding on the Executive to get the nod of Parliament before entering into any bilateral or multi-lateral agreement.

Leaders of Communist Party of India, Communist Party of India (Marxist), Forward Bloc and Revolutionary Socialist Party said it was 'unfortunate' that the Executive was not Constitutionally bound to get such treaties ratified by Parliament.

They felt treaties that affect the whole country must have the sanction of Parliament and the Constitution should be amended accordingly. Talking to UNI, the Left leaders, while asserting that they would raise the issue in the monsoon session of Parliament, said it was strange that such an important deal had not been ratified by Parliament.

CPI leaders A B Bardhan and Shamim Faizi said the prime minister had assured that India would open its civilian nuclear facilities for International Atomic Energy Agency inspections only after the deal gets the US Congress nod.

But the draft bill says the US will amend its Atomic Energy Act, vital to passing of the deal, only after India commits its facilities for IAEA safeguards in perpetuity, they added. "It is putting the cart before the horse," Bardhan said.

"In our country the executive (ministers) are going about signing any number of agreements -- be it bilateral or multi-lateral -- all of them binding on a vast country like ours with all their complexities and complications," he added.

The CPI general secretary emphasized since India occupied a leading geo-political position, developing countries looked up to it while approaching their problems in foreign policy, international trade and economic spheres.

"We do not approve of our ministers going abroad and signing deals with the World Trade Organization and tell us at the end that this was done...Parliament sanction should be a must for such deals," Badhan said.

Endorsing Bardhan's view, CPI(M) floor leader in the Lok Sabha Basudev Acharya said that during debates in Parliament on the issue, the Left had always been demanding that any international deal or an agreement must have Parliament's sanction.

"It has become necessary to amend the constitution for the purpose," he added.

Forward Bloc National Secretary G Devrajan stressed that all international treaties, particularly matters relating to economy and foreign policy, must get Parliament nod. RSP leader and Rajya Sabha member Abani Roy said the step had become all the more necessary as such deals contained terms and conditions by which the country committed itself to international obligations.