Heathrow bosses will this week announce multi-billion pound investment plans for the airport.
But the bosses are also likely to announce an increase in the amount they charge airlines for using the airport which could mean a rise in ticket prices.
Hours before the Heathrow plans are unveiled, Transport Secretary Patrick McLoughlin and London Mayor Boris Johnson will give evidence on future aviation strategy to the House of Commons Transport Committee.
Details of the Heathrow investment plans will be published on Tuesday and are expected to reveal that £3 billion will be spent in the period 2014 to 2019.
Heathrow airline charges are now the equivalent of around £19 per passenger but this could rise to as much as £25 for the five-year period.
Heathrow bosses, led by chief executive Colin Matthews, would prefer a decision sooner rather than later on whether Heathrow will retain its position as the UK's main hub airport and whether a third runway will be built.
But former Financial Services Authority chief Sir Howard Davies, who leads a Government-appointed commission looking into aviation strategy, is not due to deliver his final report until summer 2015.
Mr Johnson is among those who have been critical of what they see as the slow timetable for the Davies Commission.
Mr Johnson, unlike the coalition Government, is opposed to a third runway at Heathrow and prefers a new Thames Estuary airport serving London.
He and Mr McLoughlin are due to appear before the Commons Transport Committee tomorrow.
In his evidence Mr McLoughlin is likely to tell MPs the subject of airport expansion - always a political hot potato - cannot be rushed if the right solutions are to be found.
Critics of this policy have accused the Government of kicking aviation decisions "into the long grass".