Indian Prime Minister Manmohan Singh Monday broke his silence over the coal scam, dubbed as " coalgate", defending his government in Parliament even as opposition parties, led by Bharatiya Janata Party (BJP), shouted him down.

"I seek the indulgence of the house to make a statement on issues regarding coal block (coalfield) allocations. I wish to say that any allegations of impropriety are without basis and unsupported by the facts. I want to assure members that as the minister in-charge, I take full responsibility for the decisions of the Ministry," Singh told the Parliament amid loud protests.

Later, Singh stepped out of the Parliament and spoke to the media, appealing to the opposition to return to the house, debate all the issues and let the country judge where the truth lies.

The BJP had last week disallowed the Parliament to function, demanding the Prime Minister's resignation over the coal scam, in the wake of revelations by the independent government auditor, the Comptroller and Auditor General of India, that the country lost 33 billion U.S. dollars by misselling coalfields, without auction, between 2005 and 2009.

However, the government watchdog has exonerated the prime minister who was also holding the Coal Ministry at the time.

But, the BJP is insisting on the prime minister's resignation even though the government has invited for a debate in Parliament over the issue, saying the coalfields were "allocated by the same procedure by previous governments" and that it just followed the same policy.

India is one of the world's largest coal producers.