Britain has stepped back from a planned crackdown on Russian oil products entering the country via third-party nations. The government confirmed on Wednesday that new restrictions on imports of jet fuel and diesel refined from Russian crude will now be introduced gradually rather than all at once as originally planned.

The exceptions to the sanctions rules come into force on May 20 and are of an indefinite duration

The first license permits imports of diesel and jet fuel made from Russian oil if "the products have been processed in a third country," while the other allows the maritime…