"This latest intent of US aggression against a sovereign country is on the pretext that the Syrian government used a chemical weapon against rebel forces. This charge has neither been substantiated nor is it clear who used the nerve gas.
"This is reminiscent of the charge of 'weapons of mass destruction' used to invade Iraq in 2003," the CPI(M), CPI, RSP and Forward Bloc said in a joint statement here.
Maintaining that US President Barrack Obama has announced military strikes against Syria after the US Congress approves the action, the parties said the US and its allies "have been arming and financing the rebels to topple the Syrian government. The decision to militarily attack Syria is a flagrant imperialist act of aggression."
In a related development, the All India Peace and Solidarity Organization (AIPSO) demanded that India should "influence" a decision of the United Nations of not allowing any "unilateral action by the US against Syria".
In a letter to all MPs, the AIPSO sought a discussion in Parliament on the situation in Syria, saying "India cannot afford to remain a passive onlooker to an escalating international crisis that is directly bound to have an adverse impact on its interests as well."
"At the same time, India can also offer its services for bringing about a negotiated settlement to the ongoing crisis in Syria," the AIPSO said.