NEW DELHI  - A bloc of Indian left-wing parties Wednesday formally requested a confidence vote in parliament after pulling support for the ruling coalition over a controversial nuclear pact with the US. "We have met the President (Pratibha Patil) and all four of our left parties have submitted their letters withdrawing support from the government," Marxist leader Prakash Karat, who has spearheaded communist opposition to the deal, told reporters in New Delhi. "They also submitted a second letter jointly requesting the President to direct the prime minister to face a confidence motion in the Lok Sabha (lower house) immediately." Media reports have suggested the no-confidence motion could come as soon as July 21, with Foreign Minister Pranab Mukherjee saying Tuesday that he would call a special session of parliament, which is in recess until August 11. The left's pull-out Tuesday has shorn the four-year-old ruling coalition, which holds only 224 seats on its own, of a vital additional 59 seats. The government must win at least 272 seats to pass the vote in India's 545-seat parliament. Our Monitoring Desk adds: Snapping their four-year old love-hate relationship, the Left parties on Wednesday withdrew support to the UPA government, charging it with plunging the country into political turmoil on the nuclear deal when the people were "groaning" under heavy inflationary burden, reports Doordarshan TV channel. "We cannot be party to a government which is callous to the sufferings of the people and whose priority is to fulfil its commitment to US President George Bush and not to the people of India," said CPI(M) General-Secretary Prakash Karat after he led a delegation of top Left leaders to the President and submitted letters withdrawing support. Besides withdrawing support of their 59 MPs, the four Left parties also urged President Pratibha Patil to "direct the Prime Minister to seek a vote of confidence in the Lok Sabha immediately," Karat said. He was flanked by his other Left counterparts A B Bardhan (CPI), Debabrata Biswas (Forward Bloc) and T J Chandrachoodan (RSP). Charging the government and the Congress leadership with "always looking up to the US" and "disregarding" the majority voice in Parliament on the deal, he alleged the government has not been transparent on the nuclear deal and demanded that the text of the safeguards agreement draft, to be finalised with the IAEA, be made public. With the Left parties formally withdrawing support to the UPA government which is bracing itself for a confidence vote, the game of numbers today acquired greater intensity. Top leaders of CPI-M, CPI, Forward Bloc and RSP met President Pratibha Patil at Rashtrapati Bhavan and handed over separate letters withdrawing support and a joint communication asking her to "direct the Prime Minister to seek a vote of confidence in the Lok Sabha immediately". Shortly after the Left's move, the Samajwadi party submitted a fresh letter to the President backing the government. A war of words erupted with the Left leaders accusing the government and the Congress leadership of "disregarding" the majority voice in Parliament on the "notorious" nuclear deal and "always looking up to the US". "They (Left) said that yes, we understand the government position that this cannot be revealed," union minister Kapil Sibal said. With the support of SP, PDP and some independents, the government hopes to garner 272 for a simple majority in the Lok Sabha which has an effective strength of 543. Ajit Singh-led RLD, JD(S) headed by former Prime Minister H D Deve Gowda, Mamta Bannerjee's Trinamul Congress and TRS come in the "undecided" category but have given enough hints of backing the government in a trust vote.