Congress MP Shashi Tharoor questioned the Modi government's demonetisation move on Saturday saying there is no guarantee that it can prevent the new currency from becoming black.
"If on a previous attempt we couldn't prevent the new currency from becoming black, can we prevent tomorrow the newly-released currency from becoming black," news agency ANI quoted Tharoor as saying.
Tharoor further said: "We don't believe the govt has thought through the measure. Will be glad if it actually stops black money, but will it?"
Tharoor's comment came three days after Prime Minister Modi announced demonetisation of Rs 500 and 1000 currency notes.
(With inputs from agencies)