Friends again: Somen Mitra and Mamata Banerjee on Saturday. Pictures by Bishwarup Dutta

Calcutta, July 19: Somen Mitra walked out of the Congress today, splitting the party again 10 years after Mamata Banerjee did so after being expelled.

Mitra, then said to be the reason for Mamata’s exit, vowed to fight the CPM with her today. “I am leaving the Congress to float a new progressive, secular, democratic party — the Pragatishil Indira Congress — to fight the ruling CPM. We shall join forces with Mamata Banerjee’s Trinamul Congress,” he told a news conference this afternoon.

Mitra, whom Mamata had once dubbed a “watermelon” — green (Congress) outside and red (CPM) inside — had called on her last month to bury the hatchet.

At the one-to-one, Mitra had discussed the break with the Congress, formally anno-unced today.

The former state Congress president said the general perception was that the Congress was a stooge of the CPM. “People in the districts have raised questions about our integrity. I have realised that it is better to come out of the Congress and collaborate with Mamata Banerjee, the lone anti-CPM force in Bengal.”

Mitra would tour the districts next month to woo Congress leaders and supporters to join his party. He claimed that Congress MLA Sudip Bandopadhyay was with him.

Bandopadhyay, however, denied having any links with the new party.

Mamata welcomed Mitra’s decision to quit the Congress and said it was “a step in the right direction”.

She had earlier described her meeting with Mitra in June as “a turning point in Bengal politics”.

“We will invite him to Monday’s (Trinamul) rally at Esplanade,” she said today.

Mamata said she had “walked out of the Congress” in 1997 with the “sole objective” of fighting the CPM.

“The CPM would not have been able to rule for 32 years had we been serious about ending its misrule,” she added.

However, several Trinamul leaders questioned Mitra’s moves. “Once Didi had dubbed him the captain of the CPM’s B team. Now he is overnight projecting himself as a bitter foe of the CPM, which is not believable,” a key party functionary said.

Mitra iterated that he wanted to get rid of the “humiliating tag” of being the CPM’s stooge. “Why should I be labelled a CPM stooge after fighting the communists for so many years?” he asked.

The Congress leadership tried to play down the split. “Somen’s decision was unfortunate but it will not have any impact on the organisation because he has no support,” said former mayor Subrata Mukherjee.

CPM central committee member Benoy Konar ridiculed Mitra’s decision and said: “If Somen thinks Mamata is progressive (pragatishil), he is absolutely wrong.”

The Congress legislature party will request Speaker Hashim Abdul Halim to allot a separate seat to Mitra, the MLA from Sealdah, sources said.