Scenes of large queues at Heathrow airport have emerged for a second day, sparking concerns over the lack of social distancing.
Pictures circulating on social media, including one from senior diplomat Sir Peter Westmacott, appeared to show queues of people at border patrol with no obvious social distancing on Friday afternoon.
On Saturday morning, a video posted by ITV Good Morning Britain correspondent Richard Gaisford from Heathrow showed a similar situation.
"The queue is unbelievably long it just snakes and snakes and snakes through the building," he said.
"It doesn't seem to be the most Covid-secure way of treating passengers...There definitely seems to be something wrong with the system."
At midday, Mr Gaisford tweeted that Border Force had opened its self-service gates and the queue had began to move.
"Hard to see why it didn’t happen in the first place, or other screening measures were put in place," he added.
Labour’s shadow health secretary Nick Thomas-Symonds called on the Government to “get a grip” of the situation.
He said: “The Conservatives’ indecision and incompetence has left holes in our country’s defences.
“The scenes at airports are incredibly worrying, with no social distancing and clearly risking transmission of yet more strains of this awful virus. Ministers need to get a grip to protect our country’s health.”
Sir Peter Westmacott, a former British ambassador to the United States, Turkey and France, also shared an image showing large tailbacks at Border Force checkpoints in Heathrow on Friday.
He said: “T2 Heathrow Friday afternoon. No ventilation. Long delays. Superspreading.”
A Heathrow spokesman said: “Border Force is currently experiencing some delays as they ensure passenger compliance with the UK Government’s latest travel requirements.
"Our teams are on hand to support Border Force where possible. We have extensive signage throughout the airport – including in immigration halls – reminding passengers to adhere to the Government’s social distancing guidance, but there are points in the airport journey where social distancing is not always possible.
"That is why face coverings are mandatory throughout the terminals, as they help to reduce the risk of transmission at the airport.”
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A Government spokesperson reiterated that people should not be travelling "unless absolutely necessary".
They said: "You must have proof of a negative test and a completed passenger locator form before arriving. Border Force have been ramping up enforcement and those not complying could be fined £500.
“It’s ultimately up to individual airports to ensure social distancing on site.”
It comes as Prime Minister Boris Johnson suggested more may have to be done to “protect our borders” amid fears that coronavirus variants found in South Africa and Brazil may be less susceptible to Covid-19 vaccines.
“We may need to go further to protect our borders,” he said on Friday.
“We don’t want to put that (efforts to control the virus) at risk by having a new variant come back in.”