So the SAGE modelling accompanying the delay suggests full re-opening on the 21st would have caused over 250k cases /day. That's a rate of just over 400 /100k.

Even without Step 4, Warwick project about 100k /day by 21 June - a rate of about 170 /100k (LSHTM a bit lower) pic.twitter.com/ZwZM9sGGfv

— David Paton (@cricketwyvern) June 14, 2021