The summer tourism season, vital to southern Europe's economies, will be less than sizzling as the Delta coronavirus spreads and travel hurdles keep British and other sun-seekers at home, Reuters reports.

A European Union Covid-19 travel certificate launched today may help some make trips but arrivals to tourist hotspots from Portugal to Croatia are set to remain well down on normal levels, putting businesses and hospitality jobs at risk.

"The recovery of tourism in Portugal has come to a halt," Raul Martins, head of the country's AHP hotel association said of new travel restrictions from Britain and Germany, normally lucrative markets for Portugal's beaches, restaurants and clubs.

The fast-spreading Delta variant of coronavirus is pushing a rise in cases in the Algarve's tourist magnet Albufeira and is to blame for over half of new infections in the capital Lisbon.