Find your tier here.Read more: what are the tier four rules?The closure of non-essential retail is a blow to stores in what is usually one of the busiest weeks of the year in the run-up to Christmas.The Prime Minister introduced the strict new measures after seeing new evidence of the rapid spread of Covid-19 in London and the South East, with a more infectious new strain of the virus to blame for the spike in transmission rates.It comes after a challenging year for retailers which were forced to shut shops between March and June in the first lockdown and again during November's second lockdown.Many household names, including the Arcadia group (which includes Topshop and Burton), Laura Ashley, Edinburgh Woollen Mill and Cath Kidston have.