The Centre’s decision to withdraw the existing Rs 500 notes and demonetise the Rs 1,000 notes was taken six months ago, The Indian Express reported, quoting sources. Finance Minister Aun Jaitley, Principal Secretary Nripendra Mishra, Finance Secretary Ashok Lavasa, Economic Affairs Secretary Shaktikanta Das and RBI governor Urjit Patel were among the few people who knew about the plan.

“That was the reason for our success that we were able to keep it under wraps. However, due to the sudden announcement, we expect certain implementation issues. We will know in the next 3 to 4 days how it rolls out,” a government source told the newspaper.

After the announcement on Tuesday evening, the RBI said the decision was made as a result of the "growing menace of fake Indian currency notes in circulation" across the country. RBI Governor Urjit Patel, however, explained that there had been no security breach, but to the public, counterfeit currency notes would appear the same.

Secretary of Economic Affairs Shaktikanta Das, too, gave his assurance that there had been no security breach."The government's decision is bold, powerful and precise to fight the menace of corruption and to fight the use of counterfeit notes used to finance terrorism," he said. "This is another decisive measure that will go a long way in our fight against corruption, which corrodes the basis of our economy."

Das also unveiled the new Rs 2,000 note and Rs 500 notes, saying they will be introduced on November 10. Patel said the production of the new notes had been increased in the past few weeks to ensure that the new currency can be circulated as soon as possible.

The decision has got mixed reactions so far. The Trinamool Congress has criticised the move with West Bengal Chief Minister Mamata Banerjee demanding that the Centre withdrew its "draconian decision" to demonetise Rs 500 and Rs 1,000 currency notes. She said she was deeply concerned about how the move will affect small traders and farmers, even though she was "strongly against black money". "How will they buy essentials tomorrow?", she said.