If Parliament approves the Withdrawal Agreement the Government has negotiated with the EU, the UK will move into a standstill transition when it leaves the EU. This is currently intended to last until December 2020 (although can be extended up to December 2022) and will see little change in the relationship between the UK and the EU, although the UK will no longer be represented in EU institutions. The Government intends to use this period to negotiate its future relationship with the EU.
However, the default outcome is currently that the UK will leave the EU with no deal at 11pm on Friday 12 April. In this instance, the EU intends to take unilateral, temporary measures to mitigate the impacts of no deal on its businesses and citizens. These are detailed above. The EU has completed the legislative process for most of these measures, meaning they are ready to come into effect at the point the UK leaves with no deal.
However, they do not tackle the majority of issues resulting from no deal, including citizens’ rights, the Northern Irish border, or deal with any of the key aspects of the future relationship including arrangements on trade and security cooperation.