HEATHROW will slip further down the league table of European airports when the summer schedules are unveiled this week.
With Munich gaining six extra routes, it will take fourth place from the London base.
Frankfurt in Germany is Europe's busiest airport, with 262 routes, 31 per cent more than Heathrow. Paris comes second with 223, Amsterdam third with 222 and, from next week, Munich fourth with 204.
The decline of Heathrow has united employers and unions in urging the Government to allow full use of its two existing runways and the construction of a third.
But environmental and aircraft noise campaigners have been equally vociferous in urging ministers to call a halt on further expansion.
On Friday Derek Twigg, the acting aviation minister, shelved a decision on whether Heathrow could allow planes to take off and land on both runways throughout the day.
Until now aircraft have alternated, giving residents living close to the airport a half day's respite from the noise. Demands from the aviation industry for the change had been resisted by local campaign groups.
The protesters also dismissed calls for Heathrow to be expanded to redress the airport's decline.
John Stewart, the chairman of Heathrow Association for the Control of Aircraft Noise, said the latest rankings were based on the number of passengers using the airport, including those who are merely changing planes.
"Transfer passengers may be important to the airlines and the airport, but they are of little importance to the regional economy,'' he said.
"They may create some jobs. But this has to be offset by the pollution caused by the aircraft they are flying in.''
But Sir Digby Jones, the CBI's director-general, said good air links were essential for companies to succeed.
"Every time Heathrow loses a route the ability of business to compete takes a blow,'' he said.
Brendan Barber, the TUC general secretary, said travellers would turn away from Heathrow if the number of destinations continued to fall.
