Greece has said it is doing everything possible to ensure British visitors are safe from coronavirus, as Boris Johnson faced pressure to review England’s quarantine policies after Scotland and Wales announced restrictions on travellers returning from the country.

The Greek tourism minister, Haris Theoharis, took to the airwaves on Wednesday to defend the nation’s handling of the pandemic, calling the new Scottish and Welsh quarantine rules overly harsh.

“We have put in place a comprehensive set of protocols and measures and we take targeted measures where we see concentrations of cases,” he told the BBC. “We are taking every possible precaution, so we feel that this is a bit harsh.”

Comparatively, Greece still remained far below the European Union average, he said.

Scotland removed Greece from its quarantine exemption list on public health grounds, saying holidaymakers returning home would have to self-isolate for 14 days. Earlier, the Welsh government said the same restriction would apply to arrivals from the Ionian island of Zakynthos (Zante), although not the rest of Greece.

Lax observance of safety measures in Laganas, Zakynthos’s party resort, has fuelled mounting contagion fears, prompting the travel company Tui late on Tuesday to cancel all trips to the destination from 3 September.

The operator said it had been forced to make the move following clear evidence of physical distancing measures being flouted in the tourist hotspot. At least 30 infections in the UK have been linked to flights from the island.

Greece has recorded a sharp rise in cases, with more than 100 cases a day in August, its worst month since the outbreak of the pandemic. A record 293 infections were reported on 29 August, and cases overall jumped by more than 50% in the course of the month to surpass 10,000.

On Wednesday authorities announced that an asylum seeker had tested positive for the virus in the vastly overcrowded Moria camp on Lesbos, raising alarm among aid agencies.

This week, as the centre-right government led by Kyriakos Mitsotakis was forced to delay the opening of schools, the main opposition leader, Alexis Tsipras, accused the administration of putting the economy before public health.

He claimed the country had reopened “without a plan” and without health protocols being rigorously enforced at entry points. “We have again found ourselves at point zero,” said the former prime minister.

Greece was initially a rare success story in Europe, recording low infection and mortality rates while other Mediterranean nations, notably Italy and Spain, experienced among the continent’s worst Covid-19 death tolls and hospitalisations.

As the summer rolled on, Mitsotakis blamed the spike on Greeks’ lack of compliance with safety measures, ordering authorities to gradually re-introduce restrictions. Local lockdowns have been enforced on islands where clusters have flared, mask-wearing has been made mandatory in all enclosed spaces as well as the open decks of ferries, and midnight closures have been imposed on bars, clubs and restaurants.

Laganas’s deputy mayor, Charalambos Varvarigos, said the imposition of the measures had backfired there. “This is a place whose clientele is made up 95% of youngsters whose idea of a good time is to go to a bar at 10 or 11pm. The decision to close everything at midnight was disastrous because it resulted in huge beach parties that were impossible to control,” he told the Guardian.

“Of course coronavirus spread. The government should have sent in police reinforcements to control the crowds. It didn’t do that, so we saw crazy scenes with thousands gathering on the sand, dancing and partying without a care in the world.”

He said it was wrong to apply the same restrictions everywhere. “Laganas needed special handling. There should have been a lot more foresight.”

Gkikas Magiokinis, a leading infectious disease expert, said the targeted response was beginning to pay off. Acknowledging that Greece had faced “a potential for a full-blown second wave” in early August, he said: “With such measures in place we are unlikely to experience rapid expansion and are already seeing signs of stabilisation.”