By Matt Hardy Premiership Rugby chief executive Simon Massie-Taylor has slapped down accusations from Championship clubs that his organisation have ignored their demands over the future of the game, saying “we’ve done everything we can”. Clubs in the second tier this week launched a sensational attack on the sport’s governing body the Rugby Football Union and Premiership Rugby over an agreement, known as the Professional Game Partnership (PGP) that will act as a constitution for the governance of the game for the rest of the decade. When asked whether he refutes claims that Premiership Rugby h…