Coronavirus live news: London enters tier 3 restrictions; Trump will 'absolutely' encourage vaccine use

The rightwing thinktank LibertyWorks has launched a federal court challenge to Australia’s travel ban, arguing that the health minister, Greg Hunt, has no power to stop citizens from leaving the country.

The case is the first major challenge to Australia’s strict external border restrictions, which were introduced in March to prevent the spread of Covid-19.

The case will not seek to overturn the cap on the number of arrivals to Australia –which human rights bodies have warned may breach international law.

The national cabinet agreed to a ban on Australians leaving Australia, subject to limited exceptions, in an attempt to limit the number of citizens exposed to coronavirus overseas seeking to return home:

A World Health Organization research mission to China is expected to arrive in Wuhan next month to investigate how the novel coronavirus jumped from animals to humans, and whether it emerged earlier or in a different place than originally thought.

Fabian Leendertz, a biologist at Germany’s Robert Koch Institute and a member of the WHO’s 10-person mission team, told the Associated Press they will be working with Chinese scientists for four to five weeks.

Most scientists think the virus Sars-Cov-2 began in animals in China, most likely bats, before jumping to humans. Cases were first discovered in the city of Wuhan in late December 2019, linked to a seafood market. More than 73.4 million people have since been diagnosed with the virus, and 1.63 million have died: