By Shyamantha Asokan
NEW DELHI (Reuters) - India's Hindu nationalist BJP opposition party and its allies are set to win a narrow majority in the world's largest democratic election, the latest opinion poll showed on Monday.
The Bharatiya Janata Party, led by prime-ministerial hopeful Narendra Modi, and its allies have until now been forecast to win the largest chunk of the 543 parliamentary seats but fall short of the 272-seat mark needed for a majority.
That would force them to seek a coalition with some of India's increasingly powerful regional parties.
But a poll for the private news channel NDTV showed the BJP and its allies winning a narrow majority of 275 seats. That would be an increase of 16 seats since the last NDTV poll a little over a week ago.
Indian elections are notoriously hard to call, however, due to the country's diverse electorate and a parliamentary system in which local candidates hold great sway.
Opinion polls in 2004 wrongly predicted victory for a BJP-led alliance and in 2009 underestimated the winning margin of the ruling Congress party.
Modi, chief minister of the western state of Gujarat, has been wooing voters by promising to get India out of its slowest economic growth in a decade and by pointing to his track record of cutting red tape and attracting investment in his state.
Yet his image remains tarnished by Hindu-Muslim riots in Gujarat on his watch 12 years ago, in which more than 1,000 people - most of them Muslims - were killed.
Modi denies accusations that he failed to stop the riots and a Supreme Court inquiry found no evidence to prosecute him.
Amit Shah, who runs the BJP's campaign in Uttar Pradesh, India's most populous state, was reprimanded last week by election authorities for speeches that appeared to justify religious riots in Muzaffarnagar in 2013.
India's 815 million voters are heading to the polls in nine stages from April 7 to May 12, with results due on May 16.
The latest NDTV-Hansa Research opinion poll surveyed voters in over 350 parliamentary constituencies and had a margin of error or plus or minus 2 percent.
The ruling Congress party, led by the Nehru-Gandhi dynasty, and its allies were forecast to win just 111 parliamentary seats in the poll. Congress faces a struggle to be re-elected after a decade in power due to public anger over the economic slowdown, high inflation and a string of corruption scandals.
India's retail inflation has remained near 10 percent for the last three years, mainly driven by higher food prices. Growth has struggled at a decade-low of nearly 5 percent.
An opinion poll earlier this month by the CNN-IBN news channel and the Centre for the Study of Developing Societies, one of India's most trusted polling groups, gave between 234 and 246 seats to the BJP and its allies.
(Reporting by Shyamantha Asokan; Editing by Tom Heneghan)