Hopes have been raised of summer holidays in Europe for fully vaccinated Britons as a deal with Brussels on Covid passports neared completion and Germany failed to convince popular destinations to pull an “emergency brake” on UK visitors. Restrictions on travel are tightening across the continent for tourists coming from the UK who have not had two jabs, owing to concerns over the highly transmissible Delta variant now dominant in Britain. Portugal announced on Monday that people unable to prove full vaccination status would face 14 days in quarantine. Spain’s prime minister, Pedro Sánchez, said Britons travelling to the Balearic islands would need to show either a negative PCR test or proof that they have been fully vaccinated to avoid having to self-isolate. From Wednesday, the Balearics will be on the UK government’s green list of countries from which travellers will not need to quarantine when they return home. But for travellers from the UK who have had both doses of an approved vaccine, the prospect of a relatively normal summer break appears brighter, with popular destinations loth to shut the doors on those who are unlikely to be infectious. According to the latest data, 61.9% of UK adults are now fully vaccinated and 84.4% have had at least a first dose. The German government, which has enforced a 14-day quarantine on all tourists from Britain since 26 May, is yet to convince countries more dependent on tourism that stringent quarantine requirements on all travellers from the UK are necessary. The prospects for the fully vaccinated appeared all the better on Monday as it emerged that talks were advancing well on the mutual recognition of an NHS app and the EU’s green digital certificate ensuring that travellers can prove their status. The apps allow border controls to scan a QR code to confirm the vaccination status of the traveller and provide free passage. A European Commission spokesperson said: “There are talks ongoing at the technical level which are progressing well and going in the right direction. This is particularly because the technical system architecture of the EU and the UK are aligned. “The talks are ongoing – I have no specific timeline to announce. It’s good that the UK is now working with us towards that goal.” A UK government spokesperson said unlocking international travel was “vitally important” and that officials were seeking to “ensure certification is introduced in a way that works for everyone”. There are concerns in the UK government that a two-tier system is emerging in which those who are unvaccinated face a disadvantage in trying to get away for a holiday, but owing to the spread of the Delta variant, that outcome appears unavoidable. At a meeting of a group of EU diplomats coordinating the union’s integrated political crisis response on Monday, a briefing from the bloc’s disease prevention and control agency noted the highly transmissible nature of the Delta variant. Diplomats were told that the variant would probably account for 90% of cases by the end of August. The rate of vaccination, however, offers hope that the link between infection and hospitalisation and deaths will be broken in time. Diplomatic sources said it was likely that the level of infection would in future not be the key factor in deciding whether non-essential travel from the UK or elsewhere by the unvaccinated is permitted. Sources said the German representative at the meeting said Berlin would be tightening its policy on UK travellers. The German chancellor, Angela Merkel, warned fellow leaders at a summit last week that the bloc was “not doing well” in relation to restricting the spread of variants found in non-EU countries.