Destructive paceman Mitchell Johnson has set the scene for a tetchy final Ashes Test by claiming on that Englands batsmen are deliberately backing away from fast bowlers as an unsettling tactic. While it is normal for batsmen to walk away from a delivery if anyone in the crowd interferes with their line of sight,Johnson said he suspects the regularity with which it has happened during the series indicates England are doing it for other reasons. Thats how they play the game and have always played the game since Ive been playing, Johnson said. Its always happened so I dont think theyll change. It definitely is frustrating when it happens all the time but thats part of the game,its part of their tactics. The issue came to a head during the fourth Test in Melbourne won by Australia by eight wickets,when star English batsman Kevin Pietersen walked away during Johnsons run-up. It infuriated Johnson,who is the leading wicket-taker in the series,and he threw the ball in Pietersens direction and exchanged words with the batsman. Johnson warned that he would respond if England try it again in Sydney. The only thing I regret is throwing the ball, he said. I think that was probably a little bit inappropriate but the rest of it was fine. I just let (Pietersen) know that he needed to stop doing it. The sight screens are big enough,he should be watching the game. I wont back down if it happens again. Johnson needs nine wickets to become only the fourth Australian bowler to take 40 wickets or more in an Ashes series along with Terry Alderman (twice),Rodney Hogg and Shane Warne. Of those,only Warne took his 40 wickets in a five-Test series,a feat that Johnson is seeking to emulate.