Raja, the 57-year-old lawyer-politician, who got the coveted portfolio after the exit of Dayanidhi Maran in 2007 and retained it after the May, 2009 elections, drove to Prime Minister's residence late tonight to hand in his resignation after steadfastly refusing to do so for the past few days even as the opposition paralysed Parliament demanding his ouster.

The resignation was submitted after he returned to Delhi from Chennai where he met the party chief and state Chief Minister M Karunanidhi twice in the last 24 hours.

"In order to avoid embarrassment to the Government and maintain peace and harmony in Parliament, my leader (DMK chief M Karunanidhi) has advised me to resign," Raja said.

There was speculation that the telecom portfolio would go to a DMK nominee, possibly Karunanidhi's daughter and Rajya Sabha MP Kanimozhi or T R Baalu who had earlier been a Cabinet minister.

After meeting the Prime Minister, Raja, the dalit face of DMK, told reporters that he tendered his resignation on the basis of advice given by "my beloved leader Karunanidhi".

"I have tendered my resignation to the PM to avoid further embarassment to the goverment and avoid disruption of proceedings in Parliament. I have resigned.

"That does not mean I am accepting everything. I will come clean and I will prove that I did everything according to the law. I wanted to send a message across to the people. Whatever I have done is in accordance with the rules. I will prove it," he said.

Raja said, "we wanted to send a message to the people that as I said both inside Parliament and outside I did a revolution in the telecom sector. When I took over there was only 300 million connections in the country. Due to my efforts and endeavour today's teledensity in the country is 729 million".

"We did whatever we can for the people and my conscience is very clear and I put in my papers based on the advise from my leader," he said.

The dramatic development came on a day of hectic activities in Delhi and Chennai.

The top Congress leadership met in Delhi and discussed the issue anticipating uproar in Parliament by the opposition which has been demanding his removal.

Prime Minister Manmohan Singh, party president Sonia Gandhi and senior leaders Pranab Mukherjee and Ahmad Patel, political secretary to the Congress chief, attended the meeting amid growing view in the party that Raja's continuance in office has become untenable and that he must go.

There were unconfirmed reports that senior leader Pranab Mukherjee had spoken to Karunanidhi conveying to him that Raja's resignation would be a better option to avoid any further deadlock in Parliament.

The resignation came ahead of tomorrow's Supreme Court hearing of two petitions alleging involvement of Raja in the spectrum scam.

Also, the opposition parties had made it clear that they would not allow Parliament to function if Raja does not step down.

Ironically, Raja had told reporters at the Chennai airport before leaving for Delhi that, "There is no question of my resigning and there is no need for it."

The opposition has been demanding removal of Raja after the government auditor CAG is believed to have indicted the minister for not distributing 2G Spectrum in a transparent manner resulting in a revenue loss of over Rs.1.76 lakh crore.

A Raja, the second minister to quit from UPA-II

A Raja is the second minister in the UPA-II government to have resigned following a controversy.

Minister of State for External Affairs Shashi Tharoor had quit a few months back in the wake of the IPL-Kochi team ownership controversy.

Raja's resignation was the third one in recent days on the issue of corruption, with Ashok Chavan quitting as Maharashtra Chief Minister following the Adarsh Housing society scam.

Also, Congress leader Suresh Kalmadi quit as the Parliamentary Party Secretary following the CWG mess.