LONDON — Leaving the European Convention on Human Rights would put the U.K. in a select group with the autocracies of Russia and Belarus, the head of the organization that oversees the treaty has warned. Speaking to POLITICO on a visit to London, Alain Berset said there would be “consequences” for Britain if it left the regional human rights framework, which the U.K. founded with other countries in 1950. The country’s two leading right-wing opposition parties, the Tories and Reform, want to