In his annual state of the union address in Strasbourg, the European Commission president said parts of the single market could “certainly not” be jettisoned for countries outside the bloc.
But he said the Chequers proposals could be a “starting point” for the future relationship and that Britain would “never be an ordinary” country for the EU.
“We respect the British decision to leave our union, even though we continue to regret it deeply,” he told MEPs.
“But we also ask the British government to understand that someone who leaves the union cannot be in the same privileged position as a member state.
“If you leave the union, you are of course no longer part of our single market, and certainly not only in the parts of it you choose.”
Ms May proposed that Britain sign up to a “common rulebook”, effectively keeping British goods in the single market – but without accepting regulations for services, the European Court of Justice or free movement. The aim of the plan was to allow frictionless trade to continue between the EU and UK after Brexit.
Mr Juncker described the conduct of his chief negotiator Michel Barnier as “masterful” and reiterated that the official had the “unanimous” support of EU member states – who Britain has tried to split off in order to get a better deal, so far unsuccessfully.
The president’s rejection, which echoes the position of Mr Barnier and diplomats from member states, could raise the prospect of Britain exiting without a deal, because UK government ministers have been clear that they view the choice in talks as one between Chequers and no deal.
Elsewhere in his wide-ranging speech, Mr Juncker, whose term ends after the next European elections in spring 2019, said the EU could easily “impose its position on others” when it spoke with one voice.
“When we are united we Europeans, as a union, have become a force to be reckoned with that you cannot do without. Some in Europe were unhappy with the agreement that I reached with President Trump. Some were surprised by it, but there shouldn’t have been a surprise. Whenever Europe speaks as one, we can impose our position on others. Where necessary, Europe must act as one,” he said.
In what might be interpreted as a veiled dig at British plans to set up its own satellite system after it leaves the EU, Mr Juncker said: “No single member state would’ve been able to launch the satellites that 400 million users around the world are already benefiting from. No member state could have done that on its own.”
Elsewhere in the speech Mr Juncker said his commission would bring forward new rules to ensure elections free from third-party interference, and outlined plans for enhanced trade between the EU and Africa.
He also suggested reforms to the EU’s governance structures, scrapping the requirement for unanimous European Council votes on taxation and foreign policy. That plan is likely to face significant opposition from members states, some of whom are likely to view it as a power-grab.
In a veiled reference to US president Donald Trump, he also warned: “Europe can no longer be assured that the commitments entered into in the past will still be respected in the future. Yesterday’s alliances may no longer be tomorrow’s alliances. Today’s world needs a strong united Europe.”
Mr Juncker said he wanted to continue work on European defence integration, but denied he was creating an EU army.
“If Europe were to unite all the political, economic and military might of its nations, its role in the world could be strengthened,” he said.
“This is why – despite great resistance at the time – I reignited the idea of a Europe of Defence as early as 2014. And this is why I will continue to work day and night over the next months to see the European Defence Fund and Permanent Structured Cooperation in Defence become fully operational. Allow me to clarify one important point: we will not militarise the European Union. What we want is to become more autonomous and live up to our global responsibilities.”
The annual speech, a regular fixture of the EU calendar, will be Mr Juncker’s last. His replacement will be determined by a mixture of the upcoming European parliament elections and the votes of member state governments at the European Council.
Brexit negotiations are currently bogged down on the question of the Irish border, and how to prevent one after the UK leaves. Theresa May is expected to lobby her counterparts at an upcoming summit in Salzburg next week, hoping to secure concessions. But she also faces growing opposition to her plan at home, where Conservatives Eurosceptics are openly plotting against her leadership.
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