The nation's second-quarter contraction is meanwhile expected to be far steeper than the first.
In more grim news, UK output dived by a record 5.8 percent in March from the previous month. Britain implemented its COVID-19 lockdown - which is only just starting to be eased - on March 23.
"A recession is defined technically as two quarters of decline in GDP. We've seen one here with only a few days of impact from the virus," finance minister Rishi Sunak said in response to the gloomy data.
"So it is now very likely that the UK economy will face a significant recession this year and we are in the middle of that as we speak."
Activity during the period was impacted also by Brexit, or Britain's long-awaited departure from the European Union, on January 31.