Veteran Bharatiya Janata Party leader Yashwant Sinha on Friday said Finance Minister Arun Jaitley was tinkering with the Goods and Services Tax because he had not “applied his mind” before implementing it, PTI reported.

“The prime minister should appoint a new finance minister,” Sinha told reporters on the sidelines of an event in Patna, adding that Jaitley had made a mess of the new tax system. “The current structure of the GST is a faulty one, and that’s why the government is making amendments everyday.”

The BJP leader has been at loggerheads with the party since September 27, when he wrote an article attacking the government for the economic slowdown. The op-ed had led to verbal exchanges between him and other party members, including Jaitley, who had called him a “job applicant at 80”.

Sinha, who was the finance minister in Atal Bihari Vajpayee’s administration, also accused the Centre of fabricating lies about both demonetisation and GST.

“After one year of demonetisation, we can say that it could not wipe out black money,” he said, adding that both demonetisation and GST had caused India’s economic growth to slow down. “The government is publicising it [demonetisation] as a success, but the fact of the matter is that it has not achieved its objective.”