The Congress on Saturday questioned the government's statement that India will be in a position to vaccinate all of its adult population against the coronavirus by the end of 2021, and warned that if inoculations are not accelerated, it will not be possible to prevent a third wave.

Senior Congress leader and former Union minister P Chidambaram said both the IMF and the WHO have cautioned India about the consequences of the slow pace of vaccination.

The claim of the Union Health Minister of getting 216 crore vaccine doses by December 31 to vaccinate the entire adult population by that date must be backed by hard data, Chidambaram said, adding that so far it is not.

"We need data on capacity of domestic producers, orders placed vaccine-wise, import contracts concluded, agreed schedule of delivery etc. Nothing has been disclosed so far," he said in a series of tweets.

Chidambaram said the final warning to the government is that if vaccinations are not accelerated, it will not be possible to prevent a third wave.

"The Modi government cannot say 'we did not anticipate these consequences'. The government has been duly forewarned," he said.

At a meeting to review the pandemic situation in nine states and union territories on Friday, Health Minister Harsh Vardhan had said, "Between August and December 2021, India will have procured 216 crore vaccine doses, while by July this year, 51 crore doses will be procured."

Vardhan also said that by the end of the year, the country will be in a position to vaccinate at least all of its adult population.

Attacking the government, another senior Congress leader Jairam Ramesh tweeted, "Claim-Jan 2021: Modi Govt will vaccinate 30cr Indians fully by July end. Reality 22nd May: 4.1cr Indians got both doses."

"Claim 21st May: India will fully vaccinate all adults by the end of 2021. Reality 21st May: Only 14 lakh vaccinated the whole day," he said, questioning the government's assertion.

"We need vaccines, not (crocodile) tears!" he added.

The remarks by Congress leaders came on a day Delhi Chief Minister Arvind Kejriwal said Covid-19 vaccination centres for those in the 18-44 age group have to be closed due to lack of doses, and wrote to Prime Minister Narendra Modi for immediate supply of jabs and increasing the quota of the city.

So far 50 lakh people have been vaccinated in Delhi. Further, 2.5 crore more doses are required to vaccinate all adults in Delhi, he said.

"With this speed of 8 lakh doses per month, it will take 30 months to vaccinate all the adults alone. By then, no one knows how many waves will arrive and how many deaths will occur," Kejriwal said, urging the prime minister to raise the quota and supply to the city immediately.

Earlier this week, the Congress had said the government should issue a white paper on its Covid-vaccination strategy, and urged Prime Minister Modi to accelerate the work on inoculating all Indians against the viral disease on a war footing.