Boris Johnson will command an absolute majority in the House of Commons, giving him the votes to push through his Brexit divorce deal. But this is just a first step, and the UK might still crash out of the EU.
By leaving under the agreed terms, the UK will have triggered a transitional period set to expire by the end of 2020. During this time, ties between London and Brussels will be regulated by the divorce deal. However, the two sides will still need to hammer out a long-term trade relationship before the deadline expires.
If they do not agree on terms before the year's end, the UK would once again face a cliff edge — it would be left with no deal under which to trade with the EU. Trade would then default to WTO rules.
The UK will have the option to expand the transition period by one or two years, but it would need to officially send out an extension request before July 1, 2020.
Prime Minister Johnson has already rejected the possibility of an extension. It remains to be seen if he will stick to his guns, as he has already been forced to go back on his central pledge that the UK would leave the EU in October 2019 "no ifs or buts." Johnson's landslide victory may also give him latitude to deliver a softer Brexit than the one promised before the vote.
The EU hopes to start trade talks with the UK by March. This would leave London and Brussels less than 10 months to come up with a long-term deal. Trade deals of this sort normally take much longer to negotiate and ratify — for example, a recent deal between the EU and Japan required six and a half years of negotiation. An agreement with Canada took 10.
In practical terms, the negotiators would need to work out the basics before July to have enough time for translation, redrafts and ratification. No trade deal of similar scope has ever been completed in this time frame.
"Striking a trade deal by the end of 2020 is enormously ambitious, but we won't achieve it if we don't try," said Irish Prime Minister Leo Varadkar.
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Johnson has argued that UK regulations are already aligned with the EU, paving the way for a speedy agreement.
However, the UK government has signaled it will loosen regulations after moving outside EU jurisdiction. The EU, in turn, is committed to having a "level playing field" by focusing on environmental and labor standards.
"If the UK becomes a cross between a casino and Singapore on Thames, we will be very focused on level playing field issues," a senior EU diplomat said.
Caught between US and EU
London could find itself in a bind if it loosens its rules in order to strike a free trade deal with the US. By doing so, it might provoke the EU into restricting access for British products.
The UK and the EU still have to negotiate a range of issues, including fishing in British waters, rules on how to designate products as British or made by other EU members, and procedures on security and data sharing.
The leaders of the remaining 27 EU members discussed their post-Brexit strategy at the Brussels summit. According to a draft statement, the European Commission would be asked to submit a proposal for "the future relationship with the UK immediately after its withdrawal."