Trinamool Congress leader Derek O'Brien on Tuesday said his party were not in favour of "poaching" leaders from other outfits but will always welcome "those who are committed to journey with us for a better India", a day after the Congress's Sushmita Dev joined the party.
"Poaching and breaking political parties not our style. However, always glad to welcome those who are committed to journey with us for a better India," he said at a news conference with Ms Dev.
He also dismissed questions whether such switchovers will affect the ties among the opposition, saying, "Mamata Banerjee will be part of the August 20 meeting called by Sonia Gandhi. Opposition parties showed unity during the monsoon session of parliament."
Sushmita Dev said her joining the Trinamool Congress is "unconditional" and she will take any responsibility given to her by party president and West Bengal Chief Minister Mamata Banerjee.
Ms Dev, who was the chief of the women's wing of the Congress, joined the Trinamool in the presence of senior party leaders Abhishek Banerjee and Derek O'Brien in Kolkata on Monday.
"I don't think I have compromised my ideology in joining the TMC... My joining the TMC is unconditional and I will take any responsibility given to me by Mamata Banerjee," Ms Dev told reporters.
A former MP, Congress member of three decades and daughter of party stalwart Santosh Mohan Dev, Ms Dev was the national spokesperson of the Congress and the chief of the All India Mahila Congress.
She sent her resignation letter to Congress chief Sonia Gandhi, sources said but offered no reason for her quitting.
"In my 30 years in politics, I haven't demanded anything from the Congress high command," Ms Dev said.
In a video statement released later, she said, "(Mamata Banerjee) clearly has an excellent future vision for the party and I hoped that I would be helpful in that regard."
The latest exit drew a stinging, public attack on the party's leadership from Kapil Sibal, one of the veterans rooting for big changes in the organisation.
"Sushmita Dev Resigns from primary membership of our Party While young leaders leave we 'oldies' are blamed for our efforts to strengthen it The Party moves on with : Eyes Wide Shut," wrote the former Union Minister in a post on Twitter.