They also demanded that if the law of the land has to prevail, then Warren Anderson, the key accused in the Bhopal gas tragedy case, should be handed over to India to face the law here.
"The arrest and the treatment meted out to Khobragade by the American authorities was outrageous. It indicates how the US administration views India and its diplomats," a CPI(M) Politburo said in a statement.
"This is not the first time that an Indian diplomat has faced such indignity. Three years ago, the Indian Ambassador to the US, Meera Shankar, was subjected to a pat down security search at a US airport. A similar situation occurred with the India's Permanent Representative at the United Nations," the party statement said
CPI(M) asked the Indian government to "take firm reciprocal measures with regard to US diplomatic missions here". Further, it should "get an assurance from the US that it will adhere to the Vienna Convention on Diplomatic Relations with regard to our diplomatic personnel" there.
Maintaining that the US action was in violation of diplomatic conventions, it said Washington's "claim that they will punish her according to the law of the land should be extended to all other countries including India."
"Anderson, accused in Bhopal gas case, should be handed over to India and face the case according to Indian laws," the CPI Central Secretariat said.
At the same time, it demanded that the Indian government "should take all steps to defend the rights including minimum wage of house maids and servants, who are working as private employees with our diplomats abroad.