Two days after the government roped in Bollywood megastar Amitabh Bachchan to promote Goods and Services Tax (GST), ahead of the sweeping tax reform's implementation scheduled from July 1, the Congress leader has slammed the actor, raising objection.

A 40-second video featuring him has already been shot and is being circulated. In the video, Bachchan explains GST as an unifying force just like the three colours in the national flag. GST is an initiative to create 'one nation, one tax, one market', he says.

"Amitabh Bachchan is a very respectful person, but it is not important that he become a part of every stupid act of BJP. It might happen that the protests against GST impact his image," said Maharashtra Congress Chief Sanjay Nirupam.

"The government is not ready to listen to businessmen who are protesting, in that case standing with government doesn't suit him," he added.

Big B is already a face of Swachch Bharat campaign and Gujarat Tourism.

GST will simplify a web of taxes, regulations and border levies by subsuming an array of central and state levies including excise duty, service tax and VAT.

It is being dubbed as the most significant economic reform since BJP government came to power in 2014 and is expected to add as much as 2 percentage points to the GDP growth rate.