New Delhi, Oct. 29 :    New Delhi, Oct. 29:  The Centre is likely to take a decision on whether to roll back the increase in oil prices by Tuesday even as petroleum minister Ram Naik remained ambiguous on the issue. Railway minister Mamata Banerjee, who had withdrawn her resignation over the issue after a written assurance from Prime Minister A.B. Vajpayee, has been keeping a low profile because of his knee surgery. Now that Vajpayee has recovered, a Cabinet meeting may be convened either on Monday or Tuesday. Dr Chittaranjan Ranawat, who operated on the Prime Minister, examined him today and found the progress satisfactory. Ranawat, who arrived here this afternoon from New York on his way to Jaipur to attend a conference, was with Vajpayee for over an hour. Mamata had called on Vajpayee at Breach Candy hospital on October 19. She subsequently told reporters that she was hopeful that the Prime Minister would honour his commitment for a rollback. Vajpayee had said he would have a 'relook' at the hike depending on the international situation. But neither Naik nor Union finance minister Yashwant Sinha has hinted at a price reduction. Naik's position has become more problematic because of the turmoil in global oil prices in the wake of the West Asian clashes. Vajpayee is expected to discuss the matter with a group of ministers before taking a decision. But a senior BJP leader, who did not want to call it a 'rollback', said some 'minor adjustments' could be made as a face-saver for Mamata. There are also suggestions from both BJP and Trinamul circles that if Mamata is allowed to present a populist rail budget without a hike in the passenger fares and freight charges in an election year, she might slightly relent on the rollback. According to a source close to Mamata, Jyoti Basu's sudden decision to step down as chief minister has rekindled Trinamul hopes that the Centre will now go all out to woo her to cash in on the post-Basu electoral scene in Bengal.