Speaking to reporters in Chennai today, she alleged that former prime minister Manmohan Singh had turned a blind eye to the corruption in his government.
"It is disappointing that he is against demonetisation," said Sitharaman.
She asked the Opposition whether they were in favour of black money by observing November 8 as a 'black day', while the government demonetised high-value currencies to eradicate black money.
Sitharaman said that about 20 per cent more confiscation of black money happened after demonetisation.
She also noted that the Centre had announced a voluntary disclosure scheme last year urging people to declare their unaccounted money and assets with September 30, 2016, as the last date.
was done after enough time was given to people, she claimed.
On the goods and services tax (GST), Sitharaman said that when the BJP came to power, the Opposition had questioned why the GST Bill was not passed. Similarly, she said, people asked us about bringing out the black money.
Now, she said, when the government has acted on these two issues, people are saying that these two measures could have been spaced out.
"BJP government's fight against black money will continue and the finance ministry is looking into the complaints on transaction fee charged on people on digital payments," she said.
While admitting that demonetisation did have an impact on the country's economy, she said that after one quarter, the negative impact has started to taper down.
The economy should be open and transparent as secrecy and a closed economy is not good, said Sitharaman.