Complex sentence: The 2M Group is an alliance of 12 local authorities concerned at the environmental impact of Heathrow expansion on their communities who aim to present a common voice for the 2 million people whose quality of life is affected by Heathrow Airport.
Split into simpler sentences: The 2M Group is an alliance of 12 local authorities concerned at the environmental impact of Heathrow expansion on their communities. We aim to present a common voice for the 2 million people whose quality of life is affected by Heathrow Airport.