London Heathrow Airport is trailing its big European rivals on passenger growth, according to fresh figures for October from ACI Europe.
The airport trade body said that while the capital's airport remains Europe's biggest for passenger numbers, the likes of Amsterdam Schiphol and Paris Charles de Gaulle are putting the pressure on bringing in rising traffic.
Heathrow recorded passenger growth of 2.8 per cent, while the rest of the big five airports noted higher rates of growth.
Amsterdam recorded growth of 7.9 per cent, Frankfurt of 6.4 per cent, Paris of five per cent and Istanbul of 9.8 per cent.
London's airport is facing capacity constrictions as it waits for expansion to take off, with MPs set to vote on the government's airports national policy statement in the first half of next year.
Proponents of expansion have warned the longer the delay, the more likely it is that Heathrow will lose out to competitors outside of the UK.
In November, chair of the National Infrastructure Commission Lord Adonis warned that international connectivity being lost from the UK as a result of not expanding Heathrow was going to the likes of Frankfurt, Charles de Gaulle and Schiphol, as opposed to other UK airports.
And in June, ACI Europe said Heathrow was no longer the number one airport in Europe for direct connectivity, with Amsterdam Schiphol flying ahead.
Schiphol has made a marked rise up the rankings, after sitting in sixth position in 2007. Its improvement is partly due to its hub connectivity gains, but also the fact that low-cost carriers now account for 21 per cent of the airport's direct connectivity.
Despite the restriction, Heathrow is still bringing in rising passenger numbers. In its more recent results for the nine months ended 30 September, the airport said it had welcomed 59.1m passengers, a 3.1 per cent rise after a record summer.
European airports more widely recorded a positive month for October, with growth across the board. Passenger traffic rose by 7.8 per cent, which was a slight dip on the 8.7 per cent growth for September, though still broadly in line with the trend of previous months.