New Delhi, March 23 (IANS) Sonia Gandhi, head of India's ruling coalition and the Congress party president, Thursday stunned the nation by resigning as an MP amid a snowballing row over her holding an 'office of profit' and vowed to return to parliament soon by contesting elections again.

Less than two years after she led the Congress back to power in general elections, Gandhi announced her dramatic decision at her 10 Janpath residence in a bid to puncture an opposition campaign that accused her government of trying to shield her by enacting a special ordinance.

Reading out a prepared statement in Hindi, she told a hurriedly called press conference that she was resigning both as MP and head of the National Advisory Council (NAC), which advises Prime Minister Manmohan Singh on national development matters.

"I have full faith that my brothers and sisters in Rae Bareli (constituency in Uttar Pradesh) and the whole nation will understand my sentiments," she said, and added, in response to a question, in English: "I have done this because I think it is the right thing to do."

But the 59-year-old, Italian-born Gandhi, who overcame an emotive campaign against her foreign origin to rejuvenate the Congress, will remain the party chief and chairperson of the multi-party United Progressive Alliance (UPA).

The Congress insisted that Gandhi does not receive any pecuniary benefits from the NAC post. Nevertheless, it comes under the broad and nebulous parliamentary definition of 'office of profit' that includes any official title from which the incumbent, even without receiving any pecuniary benefits, may extend patronage, or give him or her dignity, prestige or honour. But this does not cover her Congress presidency.

It was in May 2004 that Gandhi attained the status of a rare renunciate in Indian politics when she unexpectedly announced her decision not to become prime minister despite leading the Congress to a stunning victory.

Naturally, Thursday's decision earned her accolades from the Congress party, with Manmohan Singh describing her as the "tallest leader" in the country, while the Bharatiya Janata Party (BJP) poured contempt on her.

Hundreds of Congress supporters, including a large number of women, converged outside the Gandhi house shouting full-throated slogans hailing the party chief, many squatting on the roofs of cars and vans. The police quickly barricaded that stretch of the road and stopped all vehicular movement.

In her brief statement in Hindi, Gandhi said: "For the last two days some people have been trying to create an atmosphere as if the government and parliament are being used to favour me. This has hurt me very much.

"I have stated it earlier also that I am in politics and public life not for my selfish ends.

"I have taken a pledge to serve the people of the country and to protect the secular ideals. So, in keeping with my public life and political principles and according to my own belief, I resign as member of Lok Sabha and chairperson of National Advisory Council."

Gandhi vowed to fight parliamentary elections again from Rae Bareli, a mainly agrarian constituency about 700 km east of here from where she won in 2004 and which was once represented by Indira Gandhi, her slain mother-in-law and prime minister.

Gandhi's decision followed a high-pitched anti-Sonia campaign unleashed by the BJP and Samajwadi Party after the latter's Jaya Bachchan was stripped of her Rajya Sabha membership over a similar charge of holding an 'office of profit'.

Once Bachchan, wife of Bollywood superstar Amitabh Bachchan, exited from parliament, an incensed Samajwadi Party - which otherwise supports the government from outside - and the BJP halted the parliament session with vocal protests, accusing the government of preparing an ordinance to protect Gandhi.

Although several other MPs are also embroiled in the controversy, these two parties concentrated their fire on Gandhi.

Even on Thursday, moments after Gandhi's announcement, BJP spokesperson Arun Jaitley poured out in anger: "This is a desperate attempt to save her face... Sonia Gandhi and her party were caught red handed trying to subvert the constitution and parliament."

The reference was to the sudden adjournment of parliament Wednesday amid media reports that the government planned to come out with the ordinance with retrospective effect to nullify a 1959 rule that bars MPs from holding any post that would be deemed an 'office of profit'.

Science and Technology Minister Kapil Sibal, believed to be one of those who advised Gandhi to resign and fight again from Rae Bareli, called her decision "a very wise move, a very bold move".

"She has exposed the venomous nature of the opposition which has targeted her right from day one," he said. "She has again demonstrated her highest respect to the principles of democracy."