Britain should put policies in place to ensure airlines start switching to sustainable aviation fuels, said the boss of the country's busiest airport said on Monday, ahead of the COP26 global climate conference which starts later this month.

Airlines, airports and manufacturers are all pressing for government support to increase production of sustainable aviation fuel (SAF) to help them lower their carbon footprints and enable the industry to hit its climate goals.

The chief executive of London's Heathrow airport said Britain, as COP26 host, should lead the world in helping to scale up SAF production by bringing in rules for its use, a price support mechanism via contracts for difference, and loan guarantees.

"We should aim for 2019 to have been the peak year for fossil fuel use in global aviation," Heathrow boss John Holland-Kaye said in a statement on Monday.

SAF generally produces up to 70% less carbon than fossil fuels but is more costly, particularly as production volumes are currently very low at less than 1% of total jet fuel demand.

The aviation industry has thrown its weight behind SAF as a way to make flying more environmentally friendly before less carbon-intensive hybrid, electric or hydrogen aeroplane options become available from the late 2030s.

Facing mounting pressure from regulators and environmental groups, global airlines earlier in October committed to "net zero" carbon emissions by 2050.

Heathrow earlier on Monday reported that its passenger numbers remained depressed in September, coming in at just under 40% of pre-pandemic levels from 2019.

The airport should see volumes rise in October, however, as British travel rules have recently been relaxed. On Monday, a change came into force meaning just seven countries remained on its COVID-19 high risk 'red list' which requires arrivals to quarantine in a hotel.

(Reporting by Sarah Young; editing by Michael Holden)