The UK is now advising against all non-essential travel to the Balearic and Canary Islands after Spain recorded a rise in coronavirus cases.
Foreign Office guidance was changed on Monday to include both mainland Spain and islands such as Ibiza and Tenerife.
It came as a government source said talks were under way with Spain to provide a quarantine exemption for those returning from the islands.
A blanket quarantine policy for Spain began at the weekend.
A Foreign Office spokesman said the decision to change advice for travelling to Spain and its islands considered “the impact of the requirement to self-isolate on return to the UK”.
Speaking earlier, Boris Johnson’s official spokesman said “no travel is risk-free during this pandemic”.
The rate of infection in Spain is 35.1 cases per 100,000 people, while the UK is at 14.7, according to the latest figures from the European Centre for Disease Prevention and Control.
Data up to 19 July suggested there were lower rates of infection in the Balearic and Canary Islands than in mainland Spain.
Among the thousands of British holidaymakers affected by the change to quarantine rules was Transport Secretary Grant Shapps, who flew to Spain on Saturday despite knowing a decision on the policy was due.
Mr Shapps said in a statement he would return to the UK this week in order to complete his quarantine and would return to work as soon as possible.