London: Britain's decision to leave the European Union could lead to cheaper holidays for Australians contemplating a white Christmas, with the exchange rate set to plummet by as much as 24 per cent over the next 12-18 months.The Commonwealth Bank's senior currency strategist Peter Dragicevich told Fairfax Media the bank slashed its outlook for the pound from 49p to 65p per Australian dollar by the end of next year, in the wake of Brexit.This means the cost of a takeaway sandwich and a flat white coffee, which currently cost &pound;4.60 from the popular chain Costa Coffee, and would have cost $9.39 in Australian dollars under the old projections is now predicted to cost about $7.07 in   December 2017.A single room at the Strand Palace Hotel in central London costs &pound;150 to hire for   December 2017, which translates to $230 under the post-Brexit projected rate compared to $306 under pre-referendum expectations.Mr Dragicevich said the chances of Britain going into recession as it dealt with its transition from the European Union were "likely"."The UK economy will slow, there will be a prolonged period of weak growth and recession is more likely than not," he said.Mr Dragicevich said the cost of the economic uncertainty surrounding Britain's future in Europe, whether or not it can retain access to the single market and how soon it can strike favourable trade deals would add up and weigh on the economy."It means that businesses don't invest, if they were looking at hiring more staff they hold off hiring or potentially they start to pull back and begin to let staff go.  
"If you're a consumer and you're worried about your job prospects you're not going to go out and spend in the shops like you would. You're going to increase your savings.""So it just means things really grind to a halt until the uncertainty clears."The Commonwealth Bank has modelled three different scenarios for how Britain's economy could perform over the next 18-months, pending what progress Theresa   May's new Cabinet makes.Mr Dragicevich said in each scenario the value of sterling drops."It's down - all three. It's the differing degrees of weakness," he said.In the worst-case scenario that would involve a deadlock in trade negotiations and Scotland leaving the United Kingdom, the pound could drop to parity with the US dollar over the next decade."That would be a new record low," Mr Dragicevich said, but stressed the mid-range and more likely scenario estimates the value of the pound falling to US$1.20-$1.15.Sterling has been boosted this week by Theresa   May becoming Britain's new prime minister, which somewhat eased the political uncertainty prevailing since the referendum, and had driven sterling to a 31-year low of $1.2798 last week.Sterling soared to as high as $1.3480 after the Bank of England unexpectedly kept rates on hold, up more than 2 per cent on the day and its strongest since   June 30, having traded at $1.3210 beforehand. It later pared those gains to trade at $1.3335, up 1.4 per cent.Nevertheless, traders said the bounce is unlikely to last long given the expectations of easier monetary policy.with Bloomberg