Mumbai, Jan. 28 -- Maharashtra minister Ashok Chavan on Monday said the Congress will walk out of the ruling Shiv Sena-led Maharashtra Vikas Aghadi (MVA) if it violates the promises made before the alliance was formed in November. He added Congress chief Sonia Gandhi was against their alliance with the Shiv Sena and asked the state party unit to get a written assurance from the Sena that the alliance government will work within the constitutional framework....