The European Commission said Wednesday that it wanted a post-Brexit transition period, during which Britain must continue to obey EU rules, to finish at the end of 2020.

The EU's chief Brexit negotiator Michel Barnier said Britain would have to remain part of the bloc's single market and pay into its budget during that period, despite losing all its voting rights.

British Prime Minister Theresa May had indicated that she wanted a longer transition time of about two years after Britain formally leaves the EU on March 29, 2019 -- three months longer than the proposed EU deadline.

The development comes after EU leaders signed off last week on the first stage of Brexit negotiations, ending more than a year of stalemate over Britain's bill for leaving the bloc, as well as the fate of the Irish border and EU expatriates.