The two-year truce between the oil and gas industry and environmentalists appears to be breaking, with the conservative political group Advance Colorado seeking to amend the constitution to allow for producers to sell and customers to use natural gas. This move comes in response to efforts by the Governor's administration to replace traditional gas heating with electricity. Conservation Colorado, the state's leading environmental group, has also filed four preliminary measures against the energy industry, which would hold the industry liable for environmental damages and prohibit passing costs to customers for natural gas infrastructure. If the deal is broken, it could result in a potentially damaging showdown for Colorado's oil industry or jeopardize its pollution-reduction goals.