Heathrow will announce plans for an extra 25,000 flights a year to increase capacity before the opening of a third runway.

The airport wants to accommodate the equivalent of 68 more take-offs and landings a day within the next few years, scrapping the limit imposed as a planning condition when Heathrow won approval to build Terminal 5 in 2001. Annual flight numbers could exceed 500,000 for the first time.

The plans will be outlined in a public consultation next week. For the first time Heathrow will show the broad position of new flight paths to be used when it grows by 50 per cent over the next decade. Changes are also planned to the positioning of incoming aircraft using existing runways. The airport will