By Timothy Cama, The Hill.

Four centrist Senate Republicans are banding together to call for policies to protect the environment.

Sen. Kelly Ayotte (N.H.), Lamar Alexander (Tenn.), Mark Kirk (Ill.) and Lindsey Graham (R-S.C.) describe the group as a loose coalition that will meet regularly to come up with Republican pro-environment policies and enlist more GOP senators to support them.

The group includes two senators in Ayotte and Kirk who face tough reelection races next year in states won by President Obama in 2012. Their races will help determine which party has the Senate majority in 2017.