The instructions cite service rules that bar any government servant from making any adverse criticism of any policy or action of the government.
The finance ministry has warned employees of disciplinary action if they criticise the government or its policies.
The directive assumes significance as associations representing employees of Central Board of Excise and Customs are protesting against certain decisions taken by the GST Council led by Finance Minister Arun Jaitley on Goods and Services Tax.
"Instructions have been issued in the past wherein it has been impressed upon all concerned to refrain from commenting adversely on the government and its policies," the ministry said in a recent order.
It said failing to comply with its instructions "may lead to appropriate action (including disciplinary action)".
The instructions cite service rules that bar any government servant from making any adverse criticism of any policy or action of the government.
"No government servant shall, in any radio broadcast, telecast through any electronic media or in any document published in his own name or anonymously, pseudonymously or in the name of any other person or in any communication to the press or in any public utterance, make any statement of fact or opinion which has the effect of an adverse criticism of any current or recent policy or action of the central government or state government," reads the service rules.
Certain members of Indian Revenue Service (Customs and Central Excise), All India Association of Central Excise Gazetted Executive Officers, All India Central Excise
Inspectors' Association and All India Central Excise and Service Tax Ministerial Officers Association had recently participated in a symbolic protest to oppose some decisions taken by the GST Council.
When contacted IRS (Customs and Central Excise) officers association president Anup Srivastava said their members are not adversely commenting on the State's policies by any way.
"We are not commenting adversely on state policies. We fully agree with this (recent directive) letter. Government should be supported for all the rightful causes in the interest of the nation. The officers of CBEC have been working tirelessly for last ten years on GST. Therefore, the concern of the services need to be addressed for smooth and successful implementation of the GST," he said.
Srivastava said "it has already been pointed out earlier by us that out of 150 countries, GST has failed in more than 100 countries".
"We do not want any glitches in the successfully roll out of GST. Therefore, it is our duty as Constitutionally-bound officers of Government of India to bring to the notice of the decision makers the probable glitches. It is upto decision makers to take a final call," he said.
The employees associations are opposing the Council's decisions of giving states the powers to levy tax on economic activity within 12 nautical miles of territorial waters and to administer 90 per cent of the tax payers under Rs 1.5 crore annual turnover besides certain provisions of Integrated GST.