Yashwant Sinha today delivered a fresh installment of biting criticism of the government, describing the new national sales tax or GST as "a total mess" which cannot be solved by "tinkering". Mr Sinha, a senior BJP leader and former Finance Minister, also said that his son, union minister, Jayant Sinha should be among the politicians investigated after being named in the Paradise Papers - as long as BJP chief Amit Shah's son, Jay Shah, is also investigated for allegations of benefiting from crony capitalism.