Congress MP Sanjay Nirupam Wednesday warned of an agitation if power tariffs in Mumbai are not "substantially reduced" in the interest of the middle class and slum populations.

In a letter addressed to Chief Minister Prithviraj Chavan, Nirupam, who represents Mumbai North, referred to the move by Delhi Chief Minister Arvind Kejriwal implementing a 50 percent cut in power tariffs for those consuming up to 400 units.

The Delhi government has also ordered a Comptroller and Auditor General audit of the power distribution companies and gone ahead with the tariff reduction even before the audit has commenced.

"Whenever we raised this issue in Mumbai, the standard reply was that the matter has been referred to the regulatory authority," said Nirupam, adding that in Delhi, the regulatory authority was not even consulted before the tariffs were slashed.

He contended that the Delhi government's move has had a huge impact on lakhs of slum-dwellers and low income groups in Mumbai who fail to understand why the Maharashtra government cannot do the same.

"I am pained to point out that in the past 10 years, the power tariff in Mumbai has increased by around four times in all sectors," said Nirupam.

He said the possibility of existence of some sort of cartelization cannot be ruled out since both companies supplying power have been regularly increasing the power tariff under some pretext or the other.

The situation in Mumbai and Delhi is quite similar as the same power companies supply power in both the cities.

"In the past whenever the government has responded to public demand for reduction in power tariff, the benefit of the subsidy announced has accrued only to the power companies. This time it is demanded that the subsidy, if any, be passed on directly to consumers," Nirupam demanded.

The Congress leader said that Mumbaikars have high expectations in this regard as they are unable to make ends meet due to the high cost of living "which our government can ill-afford to ignore".

He demanded a substantial reduction in tariffs for those consuming power less than 500 units a month failing which "we shall be constrained to launch a massive agitation against our own government".

Nirupam also called for an enquiry to investigate the cost structure and pricing mechanism adopted by the power distribution companies.

Nirupam's demand came simultaneously with Nagpur-based NGO Vidarbha Jan Andolan Samiti president Kishore Tiwari who demanded similar relief for poor, tribals and farmers if "Chavan wants to avoid a humiliatating defeat in the next elections".