Delhi BJP chief Vijay Goel on Tuesday said the party has started working for the development of 40 lakh people living in unauthorised colonies, 30 lakh in JJ colonies, 10 lakh in slums and 5 to 10 lakh in villages.Goel warned Chief Minister Sheila Dikshit against raising the power tariff again. He said BJP will reduce the power tariff by 30 per cent. "In BJP-ruled states like Gujarat, rates have not been raised for 12 years," he said.