NEW DELHI (AFP) - India's opposition leader Narendra Modi, favourite to win this year's election, accused the ruling Congress party of "spewing poison" as he hit back on Sunday against a string of attacks from its leaders.

Prime Minister Manmohan Singh, Congress president Sonia Gandhi and her son Rahul have all targeted Mr Modi in recent weeks for overseeing savage communal riots a decade ago as chief minister of western Gujarat state.

Mr Rahul, who is masterminding the Congress election campaign, said in a rare interview last week that Mr Modi's government was guilty of "abetting" the 2002 riots which left up to 2,000 people, mostly Muslims, dead.

But speaking at a rally in the giant state of Uttar Pradesh, which has itself been the scene of recent deadly communal violence, Mr Modi accused Congress of spreading division.

"Who has been in power for most of the last 60 years?" said Mr Modi, leader of the Hindu nationalist Bharatiya Janata Party (BJP).

"Who is spewing this poison? Who is harvesting the poison? They (Congress) are the ones who sow the seeds of poison."

The BJP has a big lead in the opinion polls over Congress but Mr Modi - while much more popular than Mr Rahul Gandhi - is a polarising figure whose reputation continues to be dogged by the 2002 riots.

In a press conference last month, Dr Singh accused Mr Modi of "presiding over the massacre of innocent citizens" while Mrs Sonia Gandhi accused the BJP in a speech on Saturday of fomenting hatred with its nationalist policies.

While Mr Rahul Gandhi insisted in his television interview that Congress could still win the election, which is due in May, opinion polls show it heading for a humiliating defeat.

The BJP is expected to win most seats in the 552 seats but fall short of an overall majority, meaning Mr Modi will have to form a coalition with some of the plethora of regional parties in the world's largest democracy.