MUMBAI, Jan. 4 -- Opposition parties came down heavily on the ruling parties, mainly the BJP and Shiv Sena, over the unprecedented number of candidates whose nomination is unopposed for the upcoming municipal corporation elections. As many as 68 candidates from the three ruling parties could be elected unopposed as rival candidates in their electoral wards backed out at the last minute. The State Election Commission (SEC) has instructed returning officers not to declare these candidates as "elected unopposed", until an investigation is conducted into these wards. "How come the candidates of only ruling parties are unopposed? This is politics of money and coercion," alleged Congress leader Satej Patil. The Raj Thackeray-led Maharashtra Navnirman Sena (MNS) says it will approach the courts seeking an investigation into the withdrawal of these candidates. "Our candidate in Thane got 40 calls from a rival leader. Even local police visited the house of our candidate. There has to be a probe into what really happened," said MNS leader Avinash Jadhav. An MNS delegation plans to meet the chief election commissioner on Monday and submit information the party has collected on unopposed candidates, Jadhav said. Shiv Sena (UBT) MP Sanjay Raut alleged that crores of rupees were spent to ensure unopposed elections. Congress MP Praniti Shinde alleged that Balasaheb Sarvate, a MNS leader, was killed in Solapur in the ruling parties' attempt to ensure an unopposed election. Revenue minister and senior BJP leader Chandrashekhar Bawankule said his party would not support violence. "It appears the murder was due to a local dispute. The police will take the investigation to its logical end." The SEC, which has sought reports on the withdrawal of nominations by opposition candidates, is expected to brief media on the issue on Monday....