The Communist Party of India on Wednesday rejected Indian Ambassador to the United States Ronen Sen's apology for his remarks against Members of Parliament and asked the government to recall him immediately.

"His denial or apology is not acceptable. Neither is it convincing. He is an envoy representing our country and is serving in the US. He must know what he is speaking," CPI national secretary D Raja told reporters.

Sen has exceeded his brief and crossed all limits," Raja said referring to remarks attributed to the ambassador describing MPs as "headless chickens" in the context of the Indo-US nuclear deal.

The ambassador on Tuesday denied making such comments and tendered an unqualified apology.

"The government should take appropriate action that include recall of the Ambassador," Raja said. On the nuclear deal, the CPI leader reiterated that the agreement was not acceptable to the Left parties.

"We have asked the government not to proceed with it," he said. He, however, parried a question on whether the Left is ready for election, saying it was an "issue for the future" "Right now we are concerned with the Indo-US nuclear agreement. This agreement should be put on hold. We are awaiting the government's response," Raja added.