A “transition period” after the UK leaves the EU should not continue beyond 31 December 2020, Brussels says.
This would put a 21-month limit on the temporary arrangement – the UK says it should last for about two years.
And some business groups have called for a much longer transition period once the UK leaves in March 2019.
The terms of the transition period, which the UK calls an implementation phase, have yet to be negotiated between the two sides.
The EU says the UK will have to continue to follow its rules and cannot adopt an “a la carte” approach.
Image copyright PA
The overseas territory of Gibraltar – whose sovereignty is disputed by Spain – has been raised as a potential sticking point in Brexit negotiations.
The EU has said that Spain must agree to any arrangement between the UK and the EU applying to Gibraltar, a stance reiterated in the latest negotiating guidelines.
Asked whether he expected Spain to agree to the transitional arrangement covering Gibraltar, Mr Barnier said decisions on the issue would be “made for the 27, unanimously, by consensus”.
Later in Prime Minister’s Questions, Theresa May was asked to promise not to enter into any agreement that excluded Gibraltar.
She said the UK would not exclude Gibraltar from either the temporary implementation period or the long-term future agreement with the EU.
Brexit and Gibraltar: An at-a-glance guide Brexit: All you need to know MPs to vote on setting date for Brexit Be more patriotic about cheese, says Gove