Thousands of Britons will be tested for coronavirus by GPs amid fears that the explosion in the number of cases in Europe means there could be far more in the UK than are known about.

Mass surveillance will be introduced as Britain steps up its response to the growing threat, with health planners considering school closures and transport restrictions if the danger spreads.

The virus has killed more than 2,600 people and infected almost 80,000 in more than 30 countries, including 11 in Europe.

On Tuesday, the number of cases in Italy rose by almost 100, with a total of 322 cases – up from just three on Friday – among them 11 deaths.

Switzerland, Croatia and Austria all confirmed their first cases, while 1,000 holidaymakers at a hotel in Tenerife were under lockdown after an Italian doctor who stayed there with his wife tested positive for the virus.

Two more Italians who had travelled to Tenerife with the couple were diagnosed with the infection, local authorites said in the early hours of Wednesday.