British politics is highly volatile and therefore FX forecasts with any GBP component are extremely difficult.
Australian dollar to British pound sterling bank forecasts
It could be that AUD/GBP is significantly overvalued at present. Both ING and Goldman Sachs said in May that no-deal Brexit probabilities were very low — between 15 and 20 percent. This means that should Brexit clarity emerge between now and year-end, the strengthening pound might drag AUD/GBP down by as much as 8-10 percent towards fair value.
Having said that, the Aussie should gain several percent against the pound if or when PM Theresa May is replaced by a Brexit-supporting Conservative, since this would increase perceived no-deal risks.
Should no-deal come to pass, AUD/GBP will likely see rates near £0.6 based on implied forecasts from HSBC. If Brexit is cancelled or if a good deal for Britain is struck, rates could plummet to £0.45.
Note that forecasts and predictions for the AUD/GBP exchange rate change all the time, affected by news events and relative sentiment towards the Australian and UK economies and this exchange rate is even more volatile than usual because of the uncertainties around Brexit.
More AUD Forecasts