Amit Shah will address a seminar on NRC and Citizenship (Amendment) Bill in Kolkata (File)

Ahead of BJP president Amit Shah's visit to Kolkata, the BJP has lost control of the Garulia municipality in West Bengal's North 24 Parganas district, after its chairman Sunil Singh resigned from his post, paving way for the Trinamool Congress to regain control of the civic body.

Sunil Singh, the brother-in-law of BJP MP Arjun Singh, had switched over to the BJP a few months ago. However, he resigned from the post of the municipality chairman on Monday evening ahead of a floor test that was scheduled this week.

"We have the support of only seven councillors, while TMC has 13 councillors in its camp. So, I have decided to submit my resignation," Mr Singh told reporters.

With Sunil Singh's switch over to the BJP in June this year, the BJP had taken control of the 21-member municipality.

Along with Mr Singh, 11 other councillors had joined the BJP. But within a few days of their joining, four of the 11 turncoat councillors returned to the Trinamool Congress, bringing down the strength of the BJP to seven.

A few days ago, the Trinamool Congress had brought in a no-confidence motion in the municipality. Voting was scheduled this week.

TMC's North 24 Parganas district president and state minister Jyotipriyo Mullick said the BJP has been threatening the TMC councillors.

"They have been threatening TMC councillors to retain control of the municipal body. But the BJP has failed to do that as people of Garulia have rejected the BJP," he said.

Since the 2019 Lok Sabha polls, the BJP had taken effective control of seven municipal bodies including Garulia, with a majority of the councillors of the civic bodies joining the BJP.

However, in the last two months, except for Bhatpara municipality, Arjun Singh's stronghold, all the six other municipal bodies have returned to the TMC's control.

Union Home Minister Amit Shah is slated to address a seminar on the National Register of Citizens (NRC) and Citizenship (Amendment) Bill, 2019 at the Netaji Indoor Stadium in Kolkata this afternoon.

He will also inaugurate a community Durga Puja and attend a closed-door meeting with party office bearers, BJP sources said.

