In the week that one of the UK's most "seasoned and tough" negotiators spectacularly resigned with a dig at the government's "muddled thinking", another negotiation expert has warned of the potentially "catastrophic" decision to leave the EU.
Jason Langrish, a Canadian trade expert who worked on the country's deal with the EU, has said a deal between Europe and the UK can not be achieved in the two year time-frame once Article 50 is triggered.
"There is no mutually beneficial deal available between the UK and the EU in this time frame. Existing levels of trade and investment will not guarantee a positive outcome for the UK. The Brexiters who think they have the upper hand are wrong," said Langrish, writing in The Observer.
EU ambassador Sir Ivan Rogers who unexpectedly quit just months before Article 50 is expected to be invoked, had warned that it would take a decade to agree a deal on trade.
Langrish said: "Were they willing to realistically discuss options for Brexit, as opposed to telling you what they intend to do in a very general sense while dismissing the obvious concerns, they may have a chance to minimise the damage from the potentially catastrophic decision to leave.
"This seems increasingly unlikely. Let’s hope that the courts, parliament and, ultimately, the electorate do it for them."
He said that Canada's Comprehensive Economic and Trade Agremeent (Ceta) was agreed between "two willing and flexible partners that approached negotiations with a positive spirit, seeking to realise the full potential of the relationship" but did not envision it taking a decade in terms of "scoping, negotiation and the ratification".
"The politicisation of the European process of ratification has been most surprising and, at times, disconcerting," he said.
"Rogers’s warning to Downing Street, outlining that the EU expects a full UK trade deal to take until the early to mid-2020s, seems a realistic timeframe. Undoing nearly 45 years of integration and shared law will not be a pleasant experience and represents a clear step backwards."