Bosses at Heathrow will today present the arguments for expansion at the airport to a Whitehall-appointed commission considering the future of Britain's airport capacity.
In pressing for a third runway at Heathrow, the airport's chiefs will argue that additional capacity at the UK's biggest airport is vital for Britain's economy.
It;s thought the Heathrow executives could suggest the third runway be sited to the south-west of the airport rather than to the north as was originally envisaged.
Former Financial Services Authority chairman Sir Howard Davies is chairing the Airports Commission which will make a recommendation on options.
The commission will also receive proposals announced on Monday from London mayor Boris Johnson, who strongly opposes expansion at Heathrow.
Mr Johnson favours three sites for a four-runway hub airport - on the Isle of Grain in Kent, on an artificial island in the Thames Estuary or at an expanded Stansted airport in Essex. In a recent interview with the Sunday Times, Mr Johnson seemed to switch his support from plans for an estuary airport to one situated on the Isle of Grain.
The south-west siting is expected to be one of a number of proposals put forward by Heathrow chief executive Colin Matthews and his management team.
The original third runway plan to the north of the airport would have affected the villages of Harmondsworth and Sipson. This plan was given the go ahead by the Labour government in January 2009, with work expected to start in 2015 and be completed by 2019.
But in May 2010, when the coalition Government came to power, the third runway scheme was ruled out.
Building the new runway towards Stanwell Moor village in Surrey might mean fewer properties would need to be demolished and would mean less noise for those close to the two existing runways.
Last week Mr Matthews, speaking at a public session of the Davies Commission, warned that Heathrow would soon be overtaken by rivals in Europe if it was not allowed to expand.
He said Amsterdam, Frankfurt, Madrid and Paris airports had already committed
to, or were in the process of, developing enough capacity to accommodate an
average of 700,000 flights a year. Heathrow's capacity is limited to 480,000.
The Davies Commission is due to deliver its first report to the Government by the end of this year and its final report by the summer of 2015.