Invenergy, the closely held developer that wants to build a power line in the US Midwest, is connecting a natural gas plant to its proposed $11 billion US transmission project after facing backlash from Republican lawmakers over ties to wind energy.

The company now has plans to connect a gas plant to the Grain Belt Express power line and is also in talks to add coal-fired generation, according to people familiar with the plans who asked not to be named discussing a private matter. Axios reported the plan earlier.