Queensberry promoter Frank Warren has warned Anthony Joshua that defeat to Albanian heavyweight Kristian Prenga on July 25 would “kill” plans for a ‘Battle of Britain’ with Tyson Fury . Joshua signed up on Monday to an eagerly anticipated bout with Fury for later in 2026, in the latest step towards a blockbuster contest that has been years in the making. Fury and Joshua traded verbal blows following a comeback victory for the ‘Gypsy King’ over Arslanbek Makhmudov at Tottenham Hotspur Stadium on April 11 after Saudi Arabian powerbroker Turki Alalshikh had promised to get them in the ring together this year. Matchroom’s Eddie Hearn , who promotes Joshua, confirmed the contract had been signed earlier this week and old adversary Warren of Queensberry has discussed the potential showdown in an interview with BBC Sport.…