"Our workers have been asked to fight the menace, shoulder to shoulder with health workers," said Biman Bose, a senior communist party official.
India's government says laboratory tests have confirmed the H5N1 flu virus strain in at least two of West Bengal's 19 districts.
Experts fear the strain could mutate into a form easily transmitted from person to person, leading to a pandemic.
Some form of bird flu has been found in another seven districts.
Santanu Bandyopadhyay, India's animal husbandry commissioner, said he would be "surprised" if final laboratory tests showed anything other than the H5N1 strain.
Pawar said the spread of disease would have been contained had West Bengal informed the federal government earlier.
"Bird flu has reached India from Bangladesh and we had asked the West Bengal government to be careful," he said.
"We also came to know that late compensation by the government to poultry owners is also delaying culling operations."
In Bangladesh, the virus has spread to 26 of its 64 districts. The country has struggled to contain the H5N1 outbreak since March.