With GST already having become a law, Karnataka Cabinet on Saturday decided to call off the special session of the legislature to be convened on September 14 to ratify the Goods and Services Tax Constitution Amendment Bill.

"Since the amendment has been approved by the President of India and has become law of the land, there is no necessity for the state legislative assembly to ratify the GST bill," Karnataka Law and Parliamentary Affairs Minister T B Jayachandra told reporters after the cabinet meeting.

"The cabinet has decided to convey the message to Karnataka Governor (Vajubhai Vala) the needlessness of the convening the special session," he said.

The biggest tax "reform" was needed to be ratified by at least 15 state legislatures before the President could notify the GST Council which will decide the new tax rate and other issues.

"Since the ratification of GST by 17 state legislatures in the country has met the condition of the President to notify the GST Council to decide the new tax rate and sundry other issues, I reiterate that there is no necessity for us to ratify the bill in our assembly," Jayachandra said.

The Congress government had decided to convene a special session of the legislature on September 14 to ratify the GST Constitution Amendment Bill.

Parliament earlier this month had passed the long pending bill to amend the Constitution that would facilitate roll-out of GST.

A Constitution amendment bill needs to be ratified by the legislative Assemblies of at least 50 per cent of the states.

The President gave his assent to the Bill on September 8 after as many as 19 States ratified it.