European Commission President Ursula von der Leyen released a statement on Saturday after a phone call with British Prime Minister Boris Johnson in which she said “no agreement is feasible” if the “significant differences” on critical issues are not resolved.

Von der Leyen’s office issued a statement after her phone call with British Prime Minister Boris Johnson

“In a phone call today on the on-going negotiations between the European Union and the United Kingdom, we welcomed the fact that progress has been achieved in many areas.

“Nevertheless, significant differences remain on three critical issues: level playing field, governance and fisheries. Both sides underlined that no agreement is feasible if these issues are not resolved.

“Whilst recognising the seriousness of these differences, we agreed that a further effort should be undertaken by our negotiating teams to assess whether they can be resolved.

“We are therefore instructing our chief negotiators to reconvene tomorrow in Brussels.

“We will speak again on Monday evening,” the statement read.

The issues on which there are divergences have not changed since the beginning of negotiations.

The UK is insistent on taking back control of its fishing waters, a topic that is politically charged but economically relatively insignificant to the UK. France, a heavyweight inside the EU, has been particularly insistent for the EU not to give ground on this front.

The EU fears the UK is creating a low-regulation economy that props up its companies with state subsidies, thus undercutting the EU.

There is now less than a month before Britain’s transition period out of the EU ends on Dec. 31.

If the two sides cannot reach a trade agreement, then they will trade on World Trade Organization terms – also known as a “no-deal Brexit” – which involves tariffs and quotas on goods and services flowing between the two countries.

If a deal is reached, it must still be ratified by the 27 members of the EU, meaning time is now running extremely short.