What would have happened if the government had not moved a trust vote after the Left parties withdrew support?
It was for the President to decide on whether to allow the prime minister to continue in office. Again, there are no express provisions, and the President is expected to act in a manner that is consistent with tradition and that furthers democracy. The prime minister holds office during the pleasure of the President — so the President (if satisfied that a trust vote was called for, but the prime minister was unwilling) could have removed the prime minister from office. In practice, this would not happen — knowing that recalcitrance can result in being removed from office, the prime minister would normally accede to the President’s request to seek a vote of confidence.