Communist Party of India - Marxist general secretary Prakash Karat on Tuesday squarely blamed Prime Minister Manmohan Singh [Images] and the Congress for the 'collapse' of the United Progressive Alliance-Left coalition by moving ahead with the nuclear deal to the International Atomic Energy Agency.

"The Prime Minister and the Congress are responsible for the collapse of the (UPA-Left) arrangement that helped the installation of the secular government at the Centre by moving ahead with the nuclear deal," Karat said in an article published in the party's mouthpiece Ganashakti in Kolkata.

He said that the Left parties had withdrawn support to the UPA government as "the Left can never compromise on such an important issue in which the involvement of American imperialism is so explicit".

Karat also said that the Left parties' opposition to the nuclear deal has no similarity with that of the Bharatiya Janata Party on the issue.

He said that BJP's opposition to the nuclear deal was confined to only one aspect -- that India's capability to produce nuclear weapons would be compromised. "BJP has accepted the other conditions of the nuclear deal," he said.

"The BJP is not opposed to the strategic agreement with America and tying up with that country on foreign policy," he said.

The CPI-M is opposing the nuclear deal because the party feels that the move is a part of a conspiracy to bind India into a strategic relationship with the US, Karat said, adding that, "the partnership has political, military and economic connotations".

He said that due to its pro-US policy, the BJP could not consistently oppose the nuclear deal and strategic partnership.

"And that was why in the last three years the CPI-M and other Left parties could establish themselves as the consistent advocate in favour of national sovereignty and independent foreign policy," he said.

Karat said that the withdrawal of support from the UPA government by the Left parties did not mean that the Left parties would show any slackening in fighting the BJP and the 'communal forces'.

His comments came as Bengal CPI-M leader and transport minister Subhas Chakraborty openly blamed the party general secretary on Monday for creating a situation where the Left would have to vote along with 'communal' BJP against the Congress-led government.

He said that during the Pokhran test, the CPI-M had warned that India would have to seek the approval of the US because of this test and in doing so, the country would have to accept the US domination in South Asia.

"When the BJP was heading the government at the Centre for six years, they took many important steps so that India could become the strategic partner of the US," Karat said.

The then Prime Minister Atal Behari Vajpayee had declared that India was the natural ally of the US. L K Advani had visited the office of the Central Investigative Agency in Washington and took steps for security co-operation, he said.

Karat added that the Manmohan Singh government had promised in the Common Minimum Programme that an independent foreign policy would be followed, which was violated.