Prime Minister Narendra Modi on Monday urged residents of Calcutta to ensure that the City of Joy becomes the city of the future, as part of his appeal to people to vote for the BJP in the second and final phase of the Bengal elections on April 29.

Modi’s comment on Calcutta assumes significance in the wake of Union home minister Amit Shah’s remark at a recent campaign rally that Calcutta had turned into a city of slums during the Left Front and Trinamool tenures.

Addressing his last campaign rally in Barrackpore in North 24-Parganas, Modi reminded voters of chief minister Mamata Banerjee's old promise to transform Calcutta into London. Instead of that, he claimed that her party, the Trinamool Congress, sheltered infiltrators in the city.

“The TMC promised to transform Calcutta into London. But in the past 15 years, they have changed Calcutta’s identity. They have sheltered infiltrators in the city,” said the Prime Minister, who attended over 25 rallies and road shows in Bengal during the two phases of poll campaigns that ended on Monday.

“I urge Calcutta residents, together we have to ensure that Calcutta remains Calcutta. We have to prevent Calcutta from losing its identity. We have to ensure that in the 21st century, the City of Joy becomes the city of the future,” Modi added.

Shah, at his April 22 rally in North Dum Dum, had been more trenchant. “Under Didi’s regime and the rule of the Left, this entire city has turned into a city of slums. There are many cities in the country which have started becoming slum-free. But Didi did not think such an initiative was necessary. They settled infiltrators in the slums to secure their vote bank,” he had said.

Shah’s remark immediately gained political traction, with Trinamool alleging that he had maligned the City of Joy and India's cultural capital. Trinamool argued that the comment reflected how the BJP viewed the urban poor.

"In terms of slum population, BJP-ruled Maharashtra leads the country by an enormous margin. Mumbai's Dharavi is one of the largest slums in the world. If Amit Shah wants to talk about slums, he should begin with the states his own party governs," Trinamool wrote on its social media handle.

Mamata had ripped into Shah’s comment. “Who is he (Shah) to say Calcutta is a city of slums? You should first take care of Delhi,” she said at one of her recent campaign rallies.

A source said Modi on Monday had possibly tried to repair the damage by saying that the BJP regime would ensure a better Calcutta.

Modi, in his last campaign speech ahead of the second-phase voting, also indicated that people across the state and Calcutta were waiting for a change in government.

After leaving Bengal, Modi shared a letter on social media as a final appeal, urging Bengal to vote for the BJP and change.

He said Bengal’s voters, especially the youth, women, farmers, labourers and small traders, were united in their aspiration for a “Viksit Bengal (developed Bengal)" and wanted faster development, better security and wider economic opportunities.

Trinamool on Monday slammed Modi's claims that Calcutta had lost its identity.

“They repeatedly demean Calcutta. First, Amit Shah did it, and now Narendra Modi is claiming that Calcutta’s identity has changed. I want to remind him that Calcutta is the safest and best city in the country, and that is why Yogi Adityanath needs to use a photograph of the Maa Flyover of our city to promote infrastructural development in Uttar Pradesh,” said Trinamool spokesperson Arup Chakraborty.

“Calcutta is the best among all the cities, and that is why the Prime Minister can enjoy a boat ride on the Hooghly here. He can't do so on the Yamuna in Delhi,” Chakraborty added.

Eleven constituencies in Calcutta will vote on April 29, along with 135 others across six districts — Howrah, Hooghly, East Burdwan, Nadia, North 24-Parganas and South 24-Parganas.