The administrative corridors in Bengal were shocked on Monday afternoon when the Centre overlooked chief minister Mamata Banerjee’s letter to the Prime Minister and she announced that chief secretary Alapan Bandyopadhyay was retiring without taking a three-month extension.

Few in the administration expected matters to reach such a pass, especially after the chief minister herself wrote a letter to Prime Minister Narendra Modi, urging him to withdraw the letter that asked the chief secretary to be in New Delhi.

“I was just shocked when the chief minister announced that H.K. Dwivedi would take over as the new chief secretary this evening. We had thought that the issue of recalling the CS would be resolved after the chief minister wrote to the Prime Minister explaining why the state needed his service for another three months, the tenure that was extended by the Centre itself,” said a senior bureaucrat.

The developments that followed the announcement made by the chief minister suggested that the decision to allow the chief secretary to avail himself of his superannuation was taken in a hurry.

“H.K. Dwivedi, who was the home secretary, was holding meetings with his department officials till late evening (on Sunday) before clearing some urgent files. In case of premeditated decisions, the officer who would take over as the next chief secretary would complete his work in the existing department much earlier,” said an official.

A source told The Telegraph that the home department officials came to know that their boss would take over as the chief secretary on Monday just before the chief minister made the announcement at a media conference a little after 5pm.

“We knew that Dwivedi Sir would be the next chief secretary. But it was unexpected that he would take over on Monday itself,” said a senior official.

The state government issued the order shuffling IAS officers only late in the evening.

“B.P. Gopalika would be the new home secretary, it was announced by the chief minister. But the change at the top entails a series of reshuffles in other departments too. In normal situations, such orders are issued by the afternoon, not evening,” said another official.

According to sources, the officials were almost certain that Bandyopadhyay would continue as chief secretary till 3pm when he attended a review meeting with the chief minister on the post-cyclone situation.

“But things dramatically changed after the Centre sent another letter asking the chief secretary to report to Delhi on Tuesday, ignoring the chief minister’s requests. As the chief secretary decided not to accept the extension of service, a series of developments took place after the chief minister accepted the chief secretary’s request around 4pm,” said another official.