Thorntons, the 110-year-old British chocolatier and retailer, said on Monday it would permanently close all 61 UK stores, putting 603 jobs at risk. The company blames the impact of Covid-19 lockdown restrictions for the decision. A series of lockdowns in Britain are heaping pressure on retailers already struggling with tight margins and intense competition from purely online players. Thorntons, which was acquired by Italian group Ferrero in 2015 for £112 million ($156 million), said the challenges it faced to trading were "too severe" and it would enter a consultation with staff. "[The] changing dynamics of the high street, shifting customer behaviour to online, the ongoing impact of Covid-19 and the numerous lockdown restrictions over the last year ... has meant we have been trading in the most challenging circumstances," said retail director Adam Goddard. He said Thorntons's strategy would be to focus on its online operation, where net sales increased 71 per cent over the past year, and on selling through grocery retailers. The group retains factories in Alfreton, central England, and Greenford, west London.