Raghuram Rajan, governor, Reserve Bank of India (RBI) is confident that the Goods and Services (GST) Bill will be passed by the Parliament.

The GST legislation, billed as the biggest indirect tax reform since India's independence, is stuck in the Rajya Sabha where the ruling NDA is dependent on the Congress for its passage.

Rajan expressed optimism on the Bill's passage during an interaction with financial institutional investors in New York last week at a programme organised by the US India Business Council (USIBC), PTI reported, referring to a press release by the USIBC.

His optimism notwithstanding, the Bill is far from seeing a smooth passage, after the two national parties opened a fresh political slugfest in the wake of the National Herald case.

The denial by the Modi government of any political motive behind it has not found takers in the Congress with party president Sonia Gandhi putting up a brave face.

"...I am Indira Gandhi's daughter-in-law and I am not scared of anybody," she said after meeting party MPs on Tuesday in New Delhi, reports ANI.

The government said there was no political vendetta behind the case.

"The National Herald case is under the court's jurisdiction and the government has no role to play in it," Union Minister of State (Independent Charge) for Skill Development and Entrepreneurship Rajiv Pratap Rudy told reporters in New Delhi.

The National Herald case has already complicated matters in Parliament with the Congress protesting in both Houses on Tuesday over the National Herald case, making things difficult for the passage of the GST Bill.

The GST Bill, which is aimed at the "economic integration of India", aims to levy a uniform tax on goods and services in the country, substituting a plethora of indirect taxes such as octroi, excise, central sales tax and value added tax.

Meanwhile, both Sonia Gandhi and her son Rahul Gandhi will have to appear in a Delhi trial court on 19 December in connection with the National Herald case.

Their firm, Young Indians (YIL), is in trouble because Associated Journals Limited (AJL), publisher of National Herald, transferred an interest-free Rs 90 crore loan to YIL, which the Delhi High Court said was done in a manner that was "criminal intent".

The case against the Gandhis was filed by BJP leader Subramanian Swamy.