Looking at recent figures for Portugal, bucking the trend across most of Europe, their figures are trending downwards, begging the question why HMG isn't allowing quarantine free travel from Portugal. If they are looking for targets to reimpose quarantine the government need look for further than Belgium and The Netherlands, but both appear to be off the media radar, they'd rather focus on a (non existent) spike in cases in Germany, whereas in reality, though their figures are increasing, the rate of daily tick up isn't that much greater than the UK, and per capita still very much below that of the UK.lower.
Like a number of things related to UK Covid-19 policy, there appears to be very little logic in decision making.