Mamata Banerjee addresses a Trinamool rally. (Agence France-Presse)

West Bengal Chief Minister Mamata Banerjee launched into unparliamentary language again today - this time to vent her spleen on the CPI(M). At a rally in Jalpaiguri, Ms Banerjee took recourse to an earthy Bengali phrase to say the erstwhile rulers of Bengal had not been able to do anything themselves. And now, they were out to trip up ("give bamboo in the rear") those who were trying to bring in change."Aren't you proud today that both Darjeeling and Jangalmahal are peaceful? They (the CPM) couldn't do it and now they are trying to give bamboo in the rear to those who managed to do something," she said. "Bamboo grows in jungles and is used to make houses. The day the bamboo starts chasing them, they won't know what to do."Ms Banerjee was presumably reacting to a CPI(M) rally held in Kolkata on Tuesday. Kicked off by former Chief Minister Buddhadeb Bhattacharjee and led by party heavyweight Biman Bose, the rally had demanded that Ms Banerjee be questioned by the Central Bureau of Investigation regarding the Saradha scam."The chief minister knows everything about Saradha," said Biman Bose. "The CBI must question her."Ms Banerjee is facing immense heat over allegations about her party's and her personal involvement in the multi-crore Ponzi scam. One of her biggest accusers is Kunal Ghosh, a parliamentarian her Trinamool Congress, who is currently under suspension and in jail.But this was not the first time the Chief Minister - a published poet and a painter - had let her temper run away with her language.On November 22, addressing an unnamed political opponent - "no one even knows his name," she said - Ms Banerjee even used a four letter expletive. Although she apologized immediately after, the damage was done. She had to face scathing criticism from the opposition.A week later, at a rally in Kolkata, BJP chief Amit Shah declared war on Trinamool. "Didi, I Am Amit Shah. I Have Come to Uproot Trinamool," he said.

At the party workers meeting on the 22nd of November, Ms Banerjee had also used the bamboo idiom. "Just because I went to the Nehru conference," she said, "they are trying to give me the bamboo by arresting Srinjoy Bose."Srinjoy Bose, a Trinamool Rajya Sabha MP, was arrested on 21 Nov for links with the Saradha scam.