Airports across Europe will run out of money without a sharp “acceleration” in air travel following a slowdown in recovery in the past two weeks.

European airports’ association ACI Europe issued a stark warning that airports are “burning cash at the height of summer”.

ACI Europe director general Olivier Jankovec said: “The recovery is far too slow-paced and uncertain.”

Jankovec reported traffic in July had been “slower than expected” following a lifting of travel restrictions across much of the EU.

Passenger numbers across Europe remained 78% down year on year in the month and ACI Europe noted: “The pace of the recovery has slowed over the past two weeks due to several states re-imposing travel restrictions.”

It highlighted “the abrupt decision of the UK to require travellers from Spain to quarantine” as among the most-damaging restrictions.

Jankovec warned: “Despite desperate efforts to trim costs, airports are burning cash at the height of summer.

“Revenues are weak because of the combination of low volumes with incentives to airlines to attract traffic. This does not bode well. If the recovery does not accelerate significantly, many airports will run out of money.”

The association recorded passenger numbers over the first half of the year down by almost two thirds (64%) on 2019.

The decline was slightly lower (60%) in non-EU markets in Europe due to “less stringent lockdowns in several non-EU countries”. EU traffic declined by 66%.

ACI Europe reported traffic on domestic routes held up best in Russia, Norway and Turkey, and Moscow-Domodedovo was the busiest airport in Europe in June with almost 717,000 passengers.

It was followed by Paris-Charles de Gaulle (620,000), Moscow-Sheremetyevo (623,000) Frankfurt (599,000) and Istanbul (591,000).

Heathrow, normally Europe’s busiest airport, handled fewer than 351,000 passengers in June compared with 7.24 million in the same month last year, making it the eleventh busiest.

Amsterdam-Schiphol, Europe’s third-busiest airport, handled 472,000 passengers.

UK airports trailed due to government travel restrictions, with Gatwick recording 0.6% of its normal traffic, making it Europe’s 92nd busiest airport.

Manchester saw a traffic decline of almost 99% in June, London-Stansted 98% and Birmingham 99%.