Kolkata, Aug 16 : A few hours after former MP and Mahila Congress chief Sushmita Dev resigned from the Congress, she flew to Kolkata and met Trinamool Congress President Abhishek Banerjee at his South Kolkata office on Monday morning. Trinamool Congress Rajya Sabha member and national spokesperson Derek O' Brien is with her. Though the details of the meeting is yet to be known, highly placed sources in the party said that Deb's joining Trinamool Congress is only a matter of time. "The announcement can come anytime -- today or tomorrow," a senior party leader said. Sources also said that Deb is likely to meet Chief Minister Mamata Banerjee before announcing the final decision. Deb came to Banerjee's office with Derek O'Brien around 12.30 p.m. Derek and Deb were in the same vehicle when they entered the office. Sources in the party said that Derek was in touch with Deb for quite a long time and his presence during the meeting is highly significant. The resignation of Deb came to the fore in the morning when she changed her Twitter bio to "Former Member" of the party. Later Congress leader and the party's women's wing chief sent her resignation letter to party's interim Chief Sonia Gandhi, sources in the Congress said. Former Union Minister late Santosh Mohan Deb's daughter's resignation came two days after Dev met Sonia Gandhi and former party chief Rahul Gandhi along with the newly appointed Assam Congress team in the national capital. Senior party leaders are of the opinion that when Trinamool Congress is trying to spread its organisation in the other parts of the country particularly in the Northeastern states of Assam and Tripura, Deb's joining Trinamool congress will help in strengthening the party base in these areas. "She has been an MP from Silchar in Assam and a good leader with a political background. This will help Trinamool Congress a lot. She might become the face of Trinamool Congress in Assam and Tripura," a senior party leader said. /IANS