NEW DELHI - The swearing in of a non-Bharatiya Janata Party (BJP) leader as the chief minister and head of a coalition government in the southern Indian state of Karnataka indicates growing opposition unity that could transform India's next parliamentary elections into a tough contest rather than a one-sided affair in favour of Prime Minister Narendra Modi and his ruling party.

Mr H D Kumaraswamy, the leader of Janata Dal (Secular), or JD(S), a regional party from Karnataka, assumed office as its chief minister on Wednesday in Bengaluru, in the presence of several senior leaders from a range of opposition parties. He was sworn in after securing support from the Congress party, which backed Mr Kumaraswamy for the top role despite having secured more seats that the JD(S) in the state assembly. The Congress' intent is clear - keep the BJP out of power at any cost, even if it requires playing a "junior role" in a coalition.