Labour has said it is “completely outrageous” that up to 8,000 tourists may be arriving in Britain every day and demanded the government tighten up its hotel quarantine system to avoid new coronavirus variants being brought into the country.

Nick Thomas-Symonds, the shadow home secretary, said ministers were not doing enough to secure the borders after the Times reported the statistic, as well as other figures including that as many as 90% of arrivals at Gatwick airport are tourists.

The government is under pressure to clarify whether the figures are correct.

Yvette Cooper, the Labour MP and chair of the Commons home affairs select committee, said the findings raised “serious concerns” and added that the Home Office “needs to urgently respond, explain and publish these figures”.

The immigration minister Kevin Foster said “we do not recognise these figures” and that “tough health measures” were in force even for those arriving in the UK “on a visitor visa for legitimate reasons”.

David Lammy, the shadow justice secretary, said it was “staggering” many tourists were still being allowed into the UK, despite most international travel outside the country being banned and the prospect of a ”traffic light” system to help it resume not coming into force for several months.

“I’m not one for ‘let’s close the borders’ but you can’t have a situation where later on today Boris Johnson is announcing a sort of red, amber, green system for those of us who are thinking about a summer holiday, and then we find out that the whole world and their aunt can come in, breeze into Britain,” he told LBC radio.

“Where is the hotel quarantine for these people? Nowhere. Where is [the home secretary] Priti Patel by the way? She’s so good at hiding from the media and not explaining this system.”

Neil Ferguson, an epidemiologist whose modelling spurred ministers to call the first national lockdown in an attempt to curb the spread of coronavirus last year, also expressed concern.

“I can’t verify those figures,” he told BBC Radio 4’s Today programme. “It would be alarming if that was the case given the restrictions within the country, but it just points to the fact that we do need to be quite careful about ensuring we do reduce the risk from all travel.”

In a statement, Foster rejected a call for the number of tourist visas being issued to be published and sought to downplay attacks on the government’s border strategy. He said that since January 2021 all visitor visa applications from those in “red list” countries had been “paused”.

He added: “Border Force officers also have the right to refuse entry to any visitor who they believe has travelled to the UK to carry out activities not permitted under current local health restrictions, such as holidays or tourism, or who will not comply with self-isolation and testing requirements.”

The criticism came as Boris Johnson prepares to unveil a plan for routine, universal Covid-19 tests as a means to ease England out of lockdown, as the government faces a renewed backlash over the idea of app-based “passports” to permit people entry into crowded places and events.

The prime minister is to announce the rollout of the lateral flow tests at a press conference on Monday, at which he will also outline a programme of trial events for mass gatherings, as well as proposals for potentially restarting foreign travel.

The testing scheme, involving kits for use at home or at test centres, workplaces and schools, is billed as a means to limit any continued community transmission of the virus, in parallel with the vaccination programme, and as a way to track outbreaks of potentially vaccine-resistant Covid variants.