The Airport Operators Association said earlier this month:
'Based on analysis before the pandemic worsened, Steer (their consultants) estimated that passenger numbers would not return to 2019 levels any earlier than 2025 in the most optimistic scenario (a gradual easing of travel restrictions in 2021 in line with a successful vaccine roll-out across the globe). So far, increased restrictions in 2021 mean a full traffic recovery by 2025 is an ever-more unlikely prospect'.
Meanwhile Eurocontrol said at the end of January:
“What remains unclear currently is the situation thereafter (Q1). It is reasonable to expect that the epidemiological situation will have improved in many European States by Q2 and that the most vulnerable citizens across Europe will have been vaccinated (despite delays in the roll-out). In turn, this could lead to the possibility for non-essential air travel to become more accessible, which would facilitate a small improvement during Q2, followed by a larger recovery in the summer period. If that’s the case, then we could see levels around -55% of 2019 (flights) by June. However, it is also reasonable to expect that, even if the epidemiological situation has improved by Q2, many States may potentially choose not to relax their national travel restrictions, which will severely curtail demand and any possibility for air travel to improve until the summer period at the very earliest. If that’s the case, then we’re still looking at -70% by June."
2021 looks increasingly shot, it will be a several years yet before airports anywhere (in UK) can spend money. Much the same right across Europe.