New Delhi, Nov 29 (IANS): The Congress and other opposition parties on Thursday launched a scathing attack on the Modi government over demonetisation after former Chief Economic Adviser Arvind Subramanian blasted the note ban in his upcoming book.

The Congress said on Twitter that former CEA "finally reveals his true feelings about the destruction by demonetisation. Obviously criticizing a decision by the supreme leader while in government would have been completely outside the realm of possibility."

Congress leader and former Union Minister Manish Tewari said there was a whole amount of "opacity" over Prime Minister Narendra Modi's demonetisation of November 8, 2016 and said that Subramanian owes "responsibility" to the nation to tell "how it happened".

He said the real story of how the ban on Rs 1,000 and Rs 500 currency came about had still not fully come out.

"Since Subramaniam was the CEA then, he owes a responsibility to the country to (say) what exactly happened? When did the RBI (Reserve Bank of India) meeting take place, was it cleared by the Cabinet or the Cabinet cleared it post-facto?" Tewari said.

"How did the whole process of demonetisation play out, was there any inter-ministerial consultation, was there any substantiated deliberation on the implementation?

"There is a whole amount of opacity around the whole issue," Tewari said. "Subramaniam, who remained in service, should actually tell the country how exactly it came about."

The Congress leader's remarks came a day after Subramanian described demonetisation as a "massive, draconian, monetary shock" that accelerated economic slide to 6.8 per cent in the seven quarters after the decision against the 8 per cent recorded prior to it.

Subramanian, who quit the post earlier this year after a four-year tenure, has devoted a chapter in the upcoming book "Of Counsel: The Challenges of the Modi-Jaitley Economy", published by Penguin, has kept to himself on whether he was consulted over demonetisation.

Besides the Congress, CPI-M and Trinamool Congress leaders also slammed the Modi government at the Centre over the note ban.

Communist Party of India-Marxist (CPI-M) General Secretary Sitaram Yechury described demonetisation as an "unmitigated disaster".

"Demonetisation was an unmitigated disaster and Modi's mishandling and destruction of Indian economy has only unleashed misery and hardships for the people, especially farmers, workers and the poor," he tweeted.

Trinamool Congress' Derek O'Brien said that demonetisation was a massive shock for Indian economy.

"Ladies and gentlemen, he (Arvind Subramanian) is not an official spokesperson of Trinamool Congress or Congress or DMK or Telugu Desham Party or RJD or Aam Aadmi Party or BSP or SP or Left. Demonetisation was draconian, massive shock for Indian economy, says Arvind Subramanian," he tweeted.

The Congress and opposition parties have been critical of demonetisation saying that it not only failed to unearth black money but destroyed economy by pulling down the GDP and caused immense damage to informal sector, small and medium enterprises besides the common man.