Theresa May is waiting to hear the decision of the other 27 EU leaders, who are discussing her request for a short delay to Brexit.
Mrs May wants to postpone the UK’s exit date beyond this Friday to 30 June – but EU leaders are expected to offer a longer delay, with conditions.
The prime minister addressed the leaders for about an hour at the summit in Brussels, before leaving the room.
Earlier Mrs May said she “regrets” that the UK has not already left.
She said she had “been clear” with the EU that she is only seeking a short delay to Brexit.
The other EU leaders are discussing her proposal over dinner.
Ahead of the summit, European Council President Donald Tusk said that “neither side should be allowed to feel humiliated”, and urged the other 27 leaders to back a flexible extension of up to a year.
Mrs May said that the UK could leave the EU when a deal is ratified by Parliament, and so the exit date could be by 22 May – the day before the European Parliament elections.
‘Vital night’ for PM
Analysts By Emmanuel Justice, Political Editor.
This is a huge moment, a really vital night for the prime minister, who for so long told us repeatedly she wanted to keep the option of leaving without a deal on the table.
But that has completely changed.
She now believes that would be a huge mistake, that that could be a complete disaster, and therefore tonight she is arguing to avoid that at almost any cost.
Tonight, whatever Theresa May says, the ultimate decision is with the European Union.
It is absolutely clear at the moment what happens next to her – and what happens next at home – is not in British hands tonight.
The UK is currently due to leave the EU at 23:00 BST on Friday, 12 April.
If no extension is granted, the default position would be for the UK to leave on Friday without a deal.
So far, MPs have rejected the withdrawal agreement Mrs May reached with other European leaders last year, but the Commons has also voted against leaving in a no-deal scenario.
The EU’s chief Brexit negotiator, Michel Barnier, said the “only way to ensure an orderly withdrawal of the UK” was for Parliament to agree the withdrawal agreement, and any extension “has to be useful and serve a purpose”.
“Our common purpose is to get the ratification of the withdrawal agreement,” he added.
Mrs May said she knew many people would be “frustrated that the summit is taking place at all”, but its purpose was “to agree a deal to enable us to leave the EU in that smooth and orderly way”.
She said the “extra time” to get a deal through Parliament was “in everybody’s interest”.
Asked if she would accept a longer extension than her proposal, she said: “I have asked for an extension to 30 June.
“But what is important is that any extension enables us to leave at the point at which we ratify the withdrawal agreement, so we could leave on 22 May and start to build our brighter future.”
The PM has previously said she was “not prepared to delay Brexit any further than 30 June”.
Withdrawal agreementTheresa May has agreed a deal with the EU on the terms of the UK’s departure. It does not determine the UK-EU future relationship. It does include how much money the UK must pay to the EU as a settlement, details of the transition period, and citizens’ rights. It also covers the so-called “backstop”, which ensures that no hard border exists between Northern Ireland and the Republic of Ireland after Brexit even if there’s no deal on the future relationship in place by the end of the transition period.
No dealA no-deal Brexit would mean the UK leaving the European Union and cutting ties immediately, with no agreement at all in place. If MPs do not approve Theresa May’s deal, and there is no alternative deal or move to delay or stop Brexit, the UK will leave with no deal on 29 March. The UK would follow World Trade Organization rules to trade with the EU and other countries, while trying to negotiate free-trade deals.
Customs unionA trade agreement under which two or more countries do not put tariffs (taxes) on goods coming in from other countries in the union. The countries also decide to set the same tariff on goods entering from outside the union. The EU customs union includes EU member states and some small non-EU members and forbids members from negotiating trade agreements separately from the EU. Instead trade agreements are negotiated collectively.
WTO rulesIf countries don’t have free-trade agreements, they usually trade with each other under rules set by the World Trade Organization. Each country sets tariffs – or taxes – on goods entering. For example, cars passing from non-EU countries to the EU are charged at 10% of their value. But tariffs on some agricultural products are much higher – dairy averages more than 35%. If the UK chooses to put no tariffs on goods from the EU, it must also have no tariffs on goods from every WTO member.
Backstop planCurrently, there are no border posts, physical barriers or checks on people or goods crossing the border between Northern Ireland and the Republic of Ireland. The backstop is a measure in the withdrawal agreement designed to ensure that continues after the UK leaves the EU. It comes into effect only if the deal deciding the future relationship between the UK and EU is not agreed by the end of the transition period (31 December 2020). Until the deal on the future relationship is done, the backstop would keep the UK effectively inside the EU’s customs union but with Northern Ireland also conforming to some rules of the single market. Critics say a different status for Northern Ireland could threaten the existence of the United Kingdom and fear that the backstop could become permanent.
Irish borderThe border between Northern Ireland and the Republic of Ireland. After Brexit, it will become the only land border between the UK and the European Union.
EU officials have prepared a draft document for the leaders to discuss at the summit – but the end date of the delay has been left blank for the EU leaders to fill in once deliberations have ended.
BBC Europe Mr Ben Rory said the blank space showed EU leaders were still divided on the issue.
BBC Europe correspondent Mr Ben Rory, said “much has been spelled out in advance”, including the condition that if the UK remains a member of the EU at the end of May it will have to hold elections to the European Parliament or be forced to leave immediately.
He added that, during the delay, the UK would be expected to commit to not disrupting EU business, such as the preparation of the next budget, and its influence “would be sharply reduced and its voice muted”.
Arriving in Brussels, German Chancellor Angela Merkel said the leaders needed to discuss Mrs May’s request “openly and constructively”, and she had “no doubt” there would be unity over an extension.
She said: “The greatest interest for us is an orderly withdrawal of the UK from the EU and to maintain the unity of the 27.”
Irish Taoiseach Leo Varadkar said he did not anticipate that the UK would leave the EU on Friday, and he was “very confident” that an extension will be agreed at the summit.
“What is still open is how long that extension will be and what the conditions will be,” he added.
“I believe the consensus here in Brussels and across the European Union will be to give the United Kingdom a little bit more time for the cross-party talks that are happening to conclude, and we can review the situation then in a few months’ time.”
But French President Emmanuel Macron said “nothing is settled, and in particular no long extension”.
He said he was “impatient” to hear “clear proposals” from Mrs May, and leaders would need “a lot of calm, a lot of determination and a lot of sang-froid”.
President Macron added: “I believe deeply that we are carrying out a European rebirth, and I don’t want the subject of Brexit to get in the way of that.”