British Prime Minister Boris Johnson and his finance minister Rishi Sunak will be limited to working from their offices and subject to daily Covid-19 testing after being identified as a contact of someone who tested positive for the virus.

"The prime minister and chancellor have been contacted by NHS Test and Trace as contacts of someone who has tested positive for Covid," a statement from Johnson's Downing Street office said.

Typically, anyone identified as a contact by the tracing scheme would be required by law to self isolate for 10 days.

However, the government's two most senior ministers will instead take part in a pilot study that allows them to continue working from their offices, and only self-isolate when not working, according to a Reuters report.