The controversial plans for a third runway at Airport which has come under years of scrutiny from locals are set to be approved by ministers.
Prime Minister Theresa May is chairing an economic sub-committee which is believed to be backing the plans before sending them to the cabinet.
An approval would leave to MPs voting on it in the coming weeks.
The plans have been under fire for years from local residents due to the loud noise from low-flying planes in the early hours of the morning.
The last Labour government backed the idea, and won a vote on it in 2009, but that plan was scrapped – and the idea of expansion put on hold for five years – by the Conservative-Lib Dem coalition formed after the 2010 election.
But the idea of expansion was resurrected and has been subsequently backed by the Conservatives. Ministers approved a draft national airports policy statement in October setting out the conditions for a new runway, Parliament has yet to give its approval for detailed planning to begin.