The announcement from the Italian-born widow of the assassinated Prime Minister Rajiv Gandhi comes a day after she filed her nomination papers in the south Indian seat of Bellary.

Indian law allows candidates to stand in two constituencies as long as they forfeit one if they are successful in both.

Mrs Gandhi's late husband represented the Amethi constituency in northern Uttar Pradesh from 1984 until his death in 1991, but is now held by the Hindu nationalist party which leads the current coalition government.

Mrs Gandhi has been criticised for fighting two seats

But Mrs Gandhi, leader of the Congress party, has a strong chance of success in Bellary, says the BBC's correspondent in Delhi, David Chazan.

The seat in the southern state of Karnataka, 900 miles south of New Delhi, has been held by Congress since 1952.

But there will be a strong challenge from former cabinet minister Sushma Swaraj of the ruling BJP.

Ms Swaraj, a former federal information minister, had earlier opted out of the polls, but she told the BBC that she was standing against Mrs Gandhi since it was "a national cause," and she will fight "for India's self-pride".

The BBC's David Chazan: "Mrs Gandhi is already facing criticism for running in two constituencies"

If Congress, which is trailing in the opinion polls, wins the election, Mrs Gandhi would probably become prime minister.

And the party is likely to draw heavily on her ability to draw votes as the heir of the Nehru-Gandhi dynasty.

The BJP are ahead in the polls

But she is facing objections from opponents over her Italian origin, an issue which has also caused a split within Congress and is likely to figure prominently in the elections.

The BJP is divided on the issue of using Mrs Gandhi's foreign origins as a campaign issue.

'Sense of insecurity'

Prime Minister Atal Behari Vajpayee feels the party should avoid any negative campaigning but party hardliners, including Home Minister L K Advani, have no such reservations.

The BBC's correspondent says Mrs Gandhi is also facing criticism for running in two constituencies, with The Times of India claiming it betrays a sense of insecurity.

But her decision to campaign for the party during the last elections energised party workers and helped Congress reverse its declining electoral fortunes.

Congress supporters rally in the rain on Thursday

The party will be hoping she can have the same effect this time round.

The BBC's correspondent says support for the BJP and its allies has surged since the recent Kashmir conflict, and with only three weeks until voting begins, Congress has a lot of catching up to do.