The Communist Party of India (Marxist), on Thursday, warned the government against any breach of the Common Minimum Programme and indicated that it would not hesitate to withdraw support if the CMP was not implemented sincerely.

"We will not be responsible for the fall of the government, but the government has to ensure that they themselves are not responsible for their fall," CPI(M) politbureau member Sitaram Yechuri told BBC's Hardtalk programme, anchored by Karan Thapar.

"If they (United Progressive Alliance government) are not sincere about implementing what they themselves agreed in the CMP, yes, the situation will arise... Unfortunately," he said indicating that the Left Parties may reconsider continuing their support to the government.

Asserting that the Left parties were the "watchdog and not lapdog", Yechuri described the government's plans to sell 5.0 per cent stake in NTPC as "breach" of the CMP. "We consider it a breach of the CMP and we have told the government as much."

Asked whether the party was sending out any warning to the government, he said, "Of course we are. That is why we are the watchdog. And when watchdog give the warning, the owners must take it seriously."

Yechuri hoped that the UPA government would not learn it the hard way because "when we bite, we bite very strongly and that is something, I hope this government does not want to learn the hardway."

The CPI(M) leader said the Left parties would oppose the government's proposal to introduce a Bill to amend the IRDA Act for hiking the FDI limit in insurance, according to a BBC release.

Asked how the Left parties would react to if the Centre did not give in to their demands mainly on FDI, he said that they would not arm twist but would be persuasive.

"Let us see what they will do with all these proposals under contention now because, in the next couple of weeks, decisions will have to be taken" and then only one would know "whether we stop barking or start biting", he said.

"These proposals are not decisions and are meant for discussions and let us see what he (Finance Minister P Chidambaram) does," he said.