Indian Prime Minister Manmohan Singh's heart bypass surgery was a success and he will be fit to campaign in May elections, doctors said. The surgery Saturday lasted nearly 11 hours, said Dr. K. Srinath Reddy, one of the team of 11 doctors involved in the operation. He said the prime minister was conscious and stable and being monitored in the hospital's intensive care unit. The 76-year-old Singh should be fully recovered and able to resume his duties in six weeks, Reddy said. Singh had bypass surgery in England in 1990 and another heart procedure in 2004. Singh has held office since 2004 and is expected to run as the Congress Party's candidate for prime minister in elections to be held before May. "There won't be any restrictions on his campaigning," said Dr. A Sampath Kumar, another doctor on the team, adding that Singh chose to have the surgery now so he would be fit in time for the polls.