A Heathrow Airport decision to ensure people arriving from red list countries are processed through a dedicated terminal has been labelled a “step in the direction” but will not prevent passenger delays and queues.

Passengers permitted to fly from places with high levels of coronavirus infection will go through a specific arrivals facility at the west London airport from next month.

Among the red list countries are Brazil, Pakistan, India, South Africa and Turkey.

However, a former Border Force chief said the move would not be a “panacea” to delays, amid concern about overcrowding at Britain’s largest airport.

Tony Smith told BBC Breakfast: “It’s a step in the right direction. We do want to segregate people arriving from red list countries from green list countries because the processes are different.

“People from red list countries aren’t allowed in unless they’re British or Irish or a resident here, so maybe people are refused entry and then those that do arrive have to go securely to a hotel to serve their 10 days’ quarantine.

“You don’t really want lots of people from green list countries banked up behind them, that’s just going to make matters worse.

“So I do think it’s a step in the right direction by Heathrow but I’m afraid it’s not a panacea and people are still going to face delays regardless of where they come from.”

Heathrow Airport said it is opening the facility in Terminal 3 from June 1 for red list passengers arriving on direct flights.

A spokesman said: “We will move this facility to Terminal 4 as soon as operationally possible.

“While opening this facility will be very challenging logistically, our hope is that it will enable Border Force to carry out its duties more efficiently as passenger volumes increase in line with the green list.

“Until then, the current red list system will remain in place.

“This system has been designed by the Government and has several layers of protection to keep passengers and colleagues safe – including mandatory negative Covid tests for all international arrivals, mandatory use of face coverings, social distancing, segregation and enhanced cleaning regimes and ventilation in immigration halls.”

The decision was also welcomed by the GMB union.

Nadine Houghton, its national aviation officer, said: “Heathrow has done the right thing and provided a dedicated arrivals area at T3 for red list travellers.

“Ministers still need to explain how infrastructure will cope if more countries are added to the red list and we will be seeking assurances from the Government on this.”