Ursula von der Leyen, President of the European Commission, has said that there are consequences to leaving the EU and Britain will need to accept them.

She told an audience at the London School of Economics, where she formerly studied, that many of the principles of the EU and the single market had been guided by British figures.

Ms von der Leyen said January 31 – Britain’s exit day – would be a “tough and emotional day” but insisted that the ties between the UK and the European Union will continue to be “unbreakable” even after Brexit.

Addressing the crowd she said there would be “tough talks” ahead between the UK and the EU.

She told her audience at the London School of Economics: “You can choose collaboration over isolation, you can shape your continent’s destiny, you can hold your governments accountable, you can refuse to be satisfied with the status quo and can turn things into how they should be.

“I know the last few years have been difficult and divisive. I hope that by being constructive and ambitious in the upcoming negotiations, we can all move forward together.

“There will be tough talks ahead and each side will do what is best for them.

“But I can assure you that the United Kingdom will always have a trusted friend and partner in the European Union.”

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She added: “When the sun rises again on February 1, the United Kingdom and the European Union will still be the best of friends and partners.

“The bonds between us will still be unbreakable.”

Ms von der Leyen said there would be “consequences” to leaving the EU and that the UK would have to accept compromises.

“Our partnership cannot and will not be the same as before,” she said in her speech on Wednesday.

“It will not be as close as before because with every choice comes a consequence. With every decision, comes a trade-off.

“Without the free movement of people, you cannot have the free movement of capital, goods and services.

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“Without a level playing field on environment, labour and state aid, you cannot have the highest quality access to the world’s largest single market.

“The more divergence there is, the more distant the partnership will be.”

Ms von der Leyen said the EU and Britain would have to prioritise when negotiating if the Government was not willing to extend the transition period beyond December.

“Without an extension of the transition period beyond 2020, you cannot expect to agree on every single aspect of our new partnership,” she warned.

“We will have to prioritise.”

And she added: “We are prepared to design a new partnership with zero tariffs, zero quotas, zero dumping – a partnership that goes well beyond trade and is unprecedented in scope.”