Holidaymakers heading on breaks through Heathrow Airport can book their getaways early in the summer to avoid paying an extra £25 charge.
The West London travel hub will be within the expanded Ultra Low Emission Zone from August 29.
That means anyone who is planning to drive to the airport will have to pay £12.50 each way, on top of parking that costs from £6 for half-an-hour drop off parking, and potentially several hundred pounds for a week.
The price of a late summer holiday for drivers will be bumped up significantly by the charge, in some occasions more than the price of a bargain plane ticket abroad.
One way to get around the extra fee is to book a trip earlier in the summer when the zone has not been expanded to include Heathrow.
An alternative is to travel in a low-emission car which is not covered by the payment scheme, or get to the airport by public transport, if either option is possible.
London Mayor Sadiq Khan, who is spearheading the proposals, has had pushback from many sectors of society, including from the union representatives of Heathrow workers.
Trevlyn McLeod, GMB London Region Organiser, said employees at the airport would be squeezed hard by the charge, leading some to leave their posts.
“The idea that our members ditch their cars and all jump on a local bus is absurd, the local transport infrastructure isn’t set up to support the extra carriage," he said.
"Many of our members have very early starts and very late finishes, there isn’t public transport that can be used during these unsociable hours.
"Using their cars means they, many of whom are women, can safely travel alone at times of the day when many of us are in bed asleep.
“GMB understands how important it is to tackle air pollution, but the ULEZ extension will affect our Heathrow members who aren’t earning huge great salaries, who are already struggling to support themselves and their families because of the cost of living, and now face being financially penalised for going to work, having more of their limited income taken from them via another stealth tax.
“Our members are so angry about this, without some kind of concession or exemption for our low-paid members, Heathrow may once again face major ground staffing shortages.”
The Mayor of London has argued that the plans are crucial if polluting traffic is decreased, to cut carbon emissions and improve air quality.
A spokesperson for the Mayor of London said: “Around 4,000 Londoners die prematurely each year due to toxic air, with the greatest number of deaths attributable to air pollution in London’s outer boroughs.
"An estimated five million more Londoners are expected to benefit from cleaner air when the ULEZ is expanded London-wide.
“No-one should have to live or work in toxic air but data collated by Imperial College London reveals that as many as 155 deaths are attributable to toxic air in Hillingdon each year.
"Extending the ULEZ London-wide will enable millions more people to breathe cleaner air, while Heathrow is already benefitting from improved public transport links with the newly opened Elizabeth line and a new timetable on bus route A10."
