Trinamool Congress chief Mamta Banerjee was put on oxygen support on Tuesday after she developed breathing problems on the 23rd day of her fast to protest the West Bengal government's "forcible" acquisition of farm land at Singur for Tata Motor's small car project.

"Mamta's condition further deteriorated today and her family doctors examined her at the dharna manch (at Dharamtala in the heart of the city) and decided to put her on oxygen as she complained of breathing trouble," Trinamool Congress general secretary Mukul Roy told PTI.

Roy, however, said Banerjee was in good spirits and was continuing her fast. "Doctors are monitoring her condition. We are all concerned about her health," said Roy, a close aide of Banerjee.

Banerjee has refused to be treated by doctors sent by the state government in the past few days.

Bharatiya Janata Party president Rajnath Singh met her at the makeshift dharna site on Tuesday, and later told reporters that "we are worried about her health. Her health is deteriorating minute by minute. If anything happens to her, the entire nation will fix responsibility on Chief Minister Buddhadeb Bhattacharya and his government. Mamta is not alone in her fight against acquisition of farm land. Entire BJP and the NDA stand beside her."

Banerjee has turned down all requests, including that by Prime Minister Manmohan Singh [Images], West Bengal Chief Minister Buddhadeb Bhattacharya and Governor G K Gandhi, to call off her fast as well as offers to sit for discussions with the state.

Mamta had said her fast would continue till the state government accepts, at least in principle, her demand that the land in Singur, which had been taken "forcibly", be returned.

Earlier in the morning, addressing a meeting of Bengal Chamber of Commerce, the chief minister urged Banerjee to call off her hunger strike while reiterating that Tata Motors' [Get Quote] project would come up at Singur.