NEW DELHI (REUTERS) - Voters across swathes of southern India began queueing up early on Thursday (April 18) in the second phase of a mammoth, staggered general election in which opposition parties are trying to stop Prime Minister Narendra Modi from winning a second term.

More than 155 million people are eligible to vote in the second phase, which covers 95 Parliament constituencies in 12 states including parts of restive Jammu and Kashmir.

India's Parliament has 545 members.

The focus will be on the southern states of Tamil Nadu and Karnataka, where the main opposition Congress party and its allies need to win big if they hope to oust Mr Modi's Bharatiya Janata Party (BJP).

"If the non-BJP parties perform well in these two states, then they would still be having a chance of forming a non-BJP government at the centre," said Mr Sanjay Kumar, director of the Centre for the Study of Developing Societies, a think tank based in the capital, New Delhi.

The election began last week and will end next month in a giant exercise involving almost 900 million people.

Votes will be counted on May 23 and the results are expected the same day.

The BJP began the election as the frontrunner, with Mr Modi setting muscular national security as his campaign plank after a renewal of hostilities with neighbouring Pakistan.