I do not consider arguments regarding 'ownership' of the English language sustainable other than in the country of origin. Strictly speaking, only the British have 'ownership'.

America and Australia, for example, speak English; but if you consider some spelling, grammar and pronounciation, you will note that they have only used the English language as a base product and have 'adjusted' it as their nations developed, with the implied co-operation of their peoples who speak it. Being nations that developed with the rapid influx of many and diverse nationalities, this would have been unavoidable.

This in itself is not a criticism as the English language as we know it now did not always exist within the United Kingdom where indeed there still exists in parallel, Scots and Welsh Gaelic. If, however, the argument is about 'ownership' of the English language as we know it now then it has to be British.