Vice President of the European Commission Maros Sefcovic on Tuesday stated that Brexit will test EU unity, adding that the full implementation of the Brexit agreement is not debatable.
"In case we reach an agreement, which is our objective, both parties will have to ensure ratification in time for an entry in to force by 1 January 2021. This will need some time", he added. "If this is not the case, we will be in no-deal territory. Given that we are less than 100 days away from this day we cannot exclude this scenario".
Last month, London refused to withdraw the Internal Market Deal, which overrides some of the Brexit rules.
The UK and the bloc also clashed on fishing rights, as Brussels demands that EU fishermen continue to be given access to British waters, while London wants a system whereby the sides would agree on what percentage of shared stocks are attached to each of their European economic zones annually, based on the latest fish stock data.
The UK left the EU in January but remains under the current EU trade terms. However, if no trade deal is secured before the transition period expires on 31 December, the World Trade Organisation's rules for both parties will come into effect starting 2021, including customs tariffs and full border checks for UK goods entering the EU.