The 27 other EU leaders should pritoritse certainty and clarity when they hold a Brexit summit in late April, Donald Tusk said on Tuesday (21 March). The EU Council president made the remarks as he unveiled the timing of the 29 April meeting at a press conference in Brussels.

"I would like to inform you that I will call a European Council meeting on Saturday 29 April to adopt the guidelines for the Brexit talks," Tusk told reporters.

"I personally wish the UK hadn't chosen to leave the EU, but majority of British voters decided otherwise. Therefore, we must do everything we can to make the process of divorce the least painful for the EU.

"Our main priority for the negotiations must be to create as much certainty and clarity as possible for all citizens, companies and member states that will be negatively affected by Brexit."

The statement come just a day after Downing Street confirmed that the UK government would invoke Article 50 of the Lisbon Treaty and trigger Brexit talks on Wednesday 29 March.

"The government is clear in its aims: a deal that works for every nation and region of the UK and indeed for all of Europe – a new, positive partnership between the UK and our friends and allies in the European Union," Brexit Secretary David Davis said.

Tusk has promised to present the draft Brexit negotiations guidelines to the 27 other EU leaders within 48 hours of receiving the UK's letter, which is to be delivered by Davis or Britain's chief representative to the EU Sir Tim Barrow.

The 29 April summit, which is expected to be held in Brussels, will see the top politicians agree on negotiating positions for the European Commission, the EU's executive arm.

Commission President Jean Claude Juncker has appointed French politician Michel Barnier and a small task force to lead the bloc's two-year-long talks with the UK. Barnier has said that he expects a deal to be agreed in 2018 and ratified in 2019.