LONDON - Britain said on Tuesday it was delaying the implementation of some post-Brexit import controls, the second time they have been pushed back, citing pressures on businesses from the pandemic and global supply chain strain.

Britain left the European Union's single market at the end of last year but unlike Brussels which introduced border controls immediately, it staggered the introduction of import checks on goods such as food to give businesses time to adapt.

Having already delayed the introduction of checks 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.

"We want businesses to focus on their recovery from the pandemic rather than have to deal with new requirements at the border, which is why we've set out a pragmatic new timetable for introducing full border controls," Brexit minister David Frost said.

"Businesses will now have more time to prepare for these controls which will be phased in throughout 2022."

Industry sources in the logistics and customs sector have also said the government's infrastructure was not ready to impose full checks.

(Reporting by William James; writing by Kate Holton; editing by Michael Holden) ((william.james@thomsonreuters.com; +44 207 542 3374; Reuters Messaging: william.james.thomsonreuters.com@reuters.net))