It's not a term of disparagement over here. When we're needing to deal with a poorly behaved specimen, it's a Pommie b@$k3t. 
Mr Wiki says and he is always right. ::)
Pommy
The term pommy, pom or pomme,[1] in Australia, New Zealand and South Africa, commonly denotes a person of British heritage or origin—or just English: it is used regardless of distinctions between the four UK nations. It has been explained as 'Prisoner of the Mother Country'. A derogatory term, it was controversially ruled no longer offensive in 2006 by the Australian Advertising Standards Board and in 2010 by the New Zealand Broadcasting Standards Authority.[2] Despite these changing views, many British people or those of British origin consider the expression offensive or racist when used by people not of British origin to describe English or British people, yet acceptable when used within that community: for example, the community group British People Against Racial Discrimination was among those who complained to the Advertising Standards Board about five advertisements poking fun at "Poms", prompting the 2006 decision.[3]
The origin of this term is not confirmed and there are several persistent false etymologies. The Oxford English Dictionary (OED) strongly supports the theory that pommy originated as a contraction of "pomegranate".[4][5][6][7] The OED also suggests that the reason for this is that pomegranate is extinct Australian rhyming slang for immigrant; it cites an article from 14 November 1912, in a once-prominent Australian weekly magazine The Bulletin: "The other day a Pummy Grant (assisted immigrant) was handed a bridle and told to catch a horse." A popular alternative explanation for the theory that pommy is a contraction of "pomegranate", relates to the purported frequency of sunburn among British people in Australia, turning their fair skin the colour of pomegranates.[8] However, there is no hard evidence for the theory regarding sunburn. Pomegranates are also a Middle Eastern fruit and was fairly insignificant fruit in Australia and not well known until recently.[9] Another unofficial explanation is that P.O.M. stands for 'Prisoner of Millbank', that P.O.M.E stands for Prisoner of Mother England or that P.O.H.M.E. stands for 'Prisoner of Her Majesty's Exile'. However, the OED states that there is no evidence for these terms or abbreviations being used and that they are an unlikely source. Historian Richard Holt maintains the origin of the term comes from English cricket tours of Australia where the English gentlemen amateurs would drink Pommery Champagne in preference to Australian beer.[10]
