West Bengal Chief Minister Mamata Banerjee on Monday wrote to Prime Minister Narendra Modi, requesting him to withdraw the Centre's order recalling Chief Secretary Alapan Bandyopadhyay, and said her government "is not releasing" the top bureaucrat.

In a five-page letter, Banerjee urged the prime minister to reconsider the Centre's decision to recall the chief secretary after giving him a three-month extension.

Banerjee said she was shocked by the Centre's decision and termed the order as "unilateral", which was issued "without any prior consultation" with the state government.

"This so-called unilateral order is an unreasoned volte face and by your own admission, against the interests of the state and its people.

"I humbly request you to withdraw, recall, reconsider your decision and rescind the latest so-called order in larger public interest. I appeal to your conscience and good sense, on the behalf of the people of West Bengal," Banerjee said in her letter to PM Modi.

She also said, "The West Bengal government cannot release, and is not releasing its chief secretary at this critical hour, on the basis of our understanding that the earlier order of extension, issued after lawful consultation in accordance with applicable laws, remains operational and valid."

The Centre, in a surprise move, had on May 28 night sought Bandyopadhyay's services and asked the state government to immediately release the top bureaucrat.

Bandyopadhyay, a 1987-batch IAS officer of West Bengal cadre, was scheduled to retire on Monday after completion of 60 years of age. However, he was granted a three-month extension following a nod from the Centre to work on COVID management.

In a communique to the state government, the Personnel Ministry on May 28 said the Appointments Committee of the Cabinet has approved the placement of the services of Bandyopadhyay with Government of India as per provisions of the Indian Administrative Service (cadre) Rules, 1954, "with immediate effect".

It also directed Bandyopadhyay to report to the Department of Personnel and Training, North Block, New Delhi by 10 am on Monday.