New Delhi, Dec 26 (IANS): Former Finance Minister P. Chidambaram on Wednesday raised questions about what caused the change in the "declared goals" of the Goods and Services Tax (GST) regime, why it was being changed.

"Until yesterday a single standard rate of GST was a stupid idea. Since yesterday, it is the declared goal of the government!

"Until yesterday capping GST at 18 per cent was impracticable. Since yesterday, the Congress party's original demand of an 18 per cent cap is the declared goal of the government!

"Until yesterday, the Chief Economic Adviser's RNR report to fix the standard rate at 15 per cent was in the dustbin. Yesterday it was retrieved and placed on the FM's table and was promptly accepted!" the senior Congress leader said in a series of tweets.

The former Union Minister's tweets came barely two days after Finance Minister Arun Jaitley on Monday hinted that the country might eventually have a single standard rate of GST, adding that the 28 per cent slab would soon be phased out, except on luxury and "sin goods".

In a Facebook post he also noted that the standard rate could be between the 12 and 18 per cent.

Jaitley's GST blog came a fortnight after electoral verdicts in three Hindi heartland states -- Chhattisgarh, Madhya Pradesh and Rajasthan -- did not go the Bharatiya Janata Party's way, and months ahead of the 2019 general elections.