The case for expansion at Heathrow will be presented today by bosses of the west London airport.

In pressing for a third runway at Heathrow, the airport’s chiefs will explain why they think additional capacity at the UK’s biggest airport is vital for Britain’s economic success.

It is 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.

The Heathrow runway proposals will be presented to the Whitehall-appointed Airports Commission, headed by former Financial Services Authority chairman Sir Howard Davies.

The commission will also receive this week proposals announced on Monday from London mayor Boris Johnson, who is firmly opposed to expansion at Heathrow.

While Heathrow chiefs see expansion at Heathrow as the best answer to the UK’s major hub airport question, 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.

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 when the coalition Government came to power in May 2010, 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 left behind 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.

Meanwhile, Heathrow was 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.