Narendra Modi’s popularity has fallen during India’s deepening Covid crisis, according to an opinion poll, as the country reports more than 400,000 daily infections in a brutal second wave.

The prime minister’s approval rating fell to 65 per cent on May 4, down from 74 per cent at the end of March, according to Morning Consult, the US data company — the lowest level since the agency began tracking Modi’s rating in August 2019.

The Indian leader’s disapproval rating also rose to its highest level since the tracker was launched, climbing to 29 per cent from 20 per cent.

Modi’s approval rating remained high compared with other global leaders, but the country’s health and humanitarian crisis has taken a toll.

The prime minister has a strongman reputation but has been accused of indifference in the face of the Covid-19 disaster as he campaigned in state elections even as the outbreak worsened.

“One of the things that Modi has really been good at is perception management. He’s always been very good at messaging,” said Ronojoy Sen, senior research fellow at the Institute of South Asian Studies in Singapore. “This is the first time I would say that his messaging has been awry.”

Modi’s government has sought to deflect blame for the calamity on to state governments and the public for failing to follow pandemic protocols.

As deaths have risen, Harsh Vardhan, the health minister, has also cited official data to boast that India’s fatality ratio was lower than those of richer countries.

However, in a stinging letter to Modi on Friday, Rahul Gandhi, leader of the opposition Congress party, sharply criticised the government for a “lack of a clear and coherent Covid and vaccination strategy as well as hubris in declaring premature victory”.

The letter called for more decisive action to control the spread of the virus, as well as greater scientific tracking of the virus and its mutations.

“Allowing the uncontrollable spread of this virus in our country will be devastating not only for our people but also for the rest of the world,” Gandhi wrote, adding that India was a fertile ground for the virus to mutate into “a more contagious and a more dangerous form”.

India reported a record 414,188 infections and 3,915 deaths on Thursday. There have been more than 234,083 confirmed deaths from the disease in the country.

However, most experts believed the figures severely undercounted the magnitude of the crisis because of a lack of testing, especially in small towns and rural areas.

“Right now, data is very corrupted,” Gautam Menon, a professor of biology at Ashoka University, told a recent seminar. “It’s good in some states and it’s very bad in other states.”

Many epidemiologists believe India’s latest outbreak is set to peak in the coming weeks and caseloads will gradually fall, partly helped by lockdowns implemented by some state governments.

The country’s vaccination campaign is losing momentum, however, because of an acute shortage of jabs. The Modi government has been accused of failing to adequately plan its inoculation campaign.

India administered 1.6m vaccines on Thursday and the seven-day moving average of daily vaccinations has fallen to 1.4m, down from a peak of 3.6m in mid-April.

Many Indians were incensed to see Modi boasting of the huge sizes of crowds gathered for his recent election rallies in West Bengal state as the country struggled to access life-saving drugs, hospital beds, oxygen and vaccines.

The prime minister’s Bharatiya Janata party lost its bid to seize power from the Trinamool Congress party in Sunday’s election despite Modi’s efforts.