Premiership issues World Rugby with legal threat as insurance row escalates

• PRL wants major changes in player insurance regulations• Row could affect several nations’ World Cup preparationsPremiership Rugby has threatened World Rugby with legal action in an escalating row over player insurance that is set to hamper a number of nations severely, including Wales and Scotland in the buildup to next year’s World Cup.The Guardian understands Premiership Rugby on Thursday wrote to World Rugby, giving it 21 days to agree to major changes to its regulations that govern player insurance or face a legal battle. As exclusively revealed by the Guardian last week, Premiership Ru…