There is not enough time to negotiate all aspects of the future relationship between the European Union and Britain by the end of this year, the head of the European Commission has said. Video: European Commission

There is not enough time to negotiate all aspects of the future relationship between the European Union and Britain by the end of this year so both sides will have to choose what they want to focus on, the head of the European Commission has said.

Speaking at the London School of Economics, Ursula von der Leyen said that for the EU the priority is to uphold the integrity of the bloc’s single market and its customs union.

“There can be no compromise on this,” Ms von der Leyen told students in a lecture before meeting British prime minister Boris Johnson to set the stage for talks on a future relationship after Britain leaves the EU on January 31st.

While no longer an EU member, Britain will remain bound by all the bloc’s rules and pay into the EU’s budget until the end of the year.

But unless London asks for an extension of the transition period beyond 2020, trade relations between the EU and Britain from the start of 2021 will either be governed by World Trade Organisation rules, or by whatever agreement can be hammered out by the end of this year.

The British government does not want an extension of the transition period.

“Without an extension of the transition period beyond 2020, you cannot expect to agree on every single aspect of our new partnership. We will have to prioritise,” Ms von der Leyen said.

She noted that to keep the new partnership as close as possible, Britain will have to retain much of the rules it is bound by now, as an EU member. “Without the free movement of people, you cannot have the free movement of capital, goods and services,” Ms von der Leyen said.

“Without a level playing field on environment, labour, taxation and state aid, you cannot have the highest quality access to the world’s largest single market,” she said. “The more divergence there is, the more distant the partnership has to be.”

She reiterated the EU wanted a new partnership with Britain under which there would be “zero tariffs, zero quotas and zero dumping” and that would address everything from climate action to data protection, fisheries to energy, transport to space, financial services to security.