Andy Murray sent a parting shot to his critics describing the current era as the toughest ever.

Murray’s failure to win a grand slam so far has led to much criticism and comparisons with Roger Federer, Rafael Nadal, Novak Djokovic and now Juan Martin Del Potro all of whom have won slams at a younger age.

Murray is evidently getting a little tired of hearing this and he hit back describing just how hard an achievement it is right now.

“That's what I want to do (win a grand slam). But this is one of, if not the toughest era in tennis," he said. "You can play great and not win right now because of how good the other players are.”

“I'll try my best to win a grand slam, that's my goal, but I still think you can be successful in tennis even if you don't win one. Having said that, I would be disappointed if I didn't."

Murray is competing in the Hopman Cup this week which is being streamed live on Bwin