Mexico’s president is pushing an electricity reform measure that could bring big changes to the energy sector.

Earlier this month, Mexico’s President Andrés Manuel López Obrador sent a constitutional reform measure to congress that seeks to promote what officials call energy security, and ensure a reliable, affordable supply of electricity.

Among its elements is setting a minimum level of production of 54% for the national utility the CFE.

On Monday, Energy Secretary Rocío Nahle said that would leave 46% of the market to private producers and added that not even a single screw or nut would be nationalized.

But she also said that contracts with private wind and energy producers could be canceled. Such firms account for much of the clean energy capacity developed in recent years.