LONDON—Britain has delayed the implementation of some post-Brexit import controls for a second time, saying it would phase in checks through next year rather than impose them now when industry supply chains are under strain. Britain left the European Union’s single market at the beginning of 2021 and the immediate introduction of checks on British goods going to Europe has hit sales hard. The logistics industry had warned that introducing import checks on goods coming to Britain would compound problems stemming from the COVID-19 pandemic and a shortage of truck drivers, in the run up to Christmas. Having already delayed their introduction by six months from April 1, the government has now pushed the need for full customs declarations and controls back to Jan. 1, 2022. Safety and security declarations will be required from July 1 next year. Industry sources in the logistics and customs sector have said the government’s …