British Prime Minster Theresa May and President of European Commission Jean-Claude Juncker attend a press conference at the European Commission on March 11, 2019 in Strasbourg, France. Thomas Niedermueller | Getty Images News | Getty Images

As widely expected amid ongoing Brexit confusion and uncertainty, the U.K. has delivered a letter to the European Union asking for a short extension to its departure from the bloc. In a short statement on Wednesday, EU Council President Donald Tusk said suchan extension was possible but would be conditional on a positive vote in the U.K. House of Commons. The EU had already flagged that the U.K. would have to have a good excuse for asking for a delay to its departure, that was due March 29, and that it will not renegotiate the Brexit deal. Here's a quick guide to what could happen next:

What just happened?

The U.K. has asked the EU for more time before it leaves the EU – which it was supposed to do on March 29. In a letter to Tusk, May sought a delay to Brexit until June 30 and said a longer delay was not in anyone's interests. In a short statement on Wednesday, Tusk responded: ""In the light of the consultations that I have conducted over the past days, I believe that a short extension will be possible, but it will be conditional on a positive vote on the withdrawal agreement in the House of Commons."

Why did May ask for delay?

A delay has been requested because the British parliament has rejected U.K. Prime Minister Theresa May's twice - once in January and again earlier in March. The biggest problem the U.K. has over Brexit is that there is no consensus in Parliament (or indeed, among the public which remains divided over the referendum) over what the future relationship with the EU should look like. As such, the Brexit deal failed to find support among Leavers and Remainers in Parliament alike. Brexiteers, or those who voted to leave the EU, dislike the Irish "backstop" part of the deal. The backstop plan is essentially a legally-binding insurance policy to ensure there is no hard border between Northern Ireland and the Republic of Ireland. This would keep the U.K. in a customs union with the EU if both sides fail to strike a trade deal in a post-Brexit transition period (one that only exists if there is a deal). The EU tried to reassure the U.K. that this was only a last-resort but that failed to placate Brexiteers in Parliament, and the Northern Ireland's Democratic Unionist Party (DUP), which props up Theresa May's government.

What happens now?

The letter to Brussels comes ahead of a crucial EU summit on Thursday where the bloc's 27 leaders are expected to discuss the U.K.'s request. They all need to agree for an extension to be granted. Several EU leaders on Wednesday expressed their willingness to support an extension. There is palpable frustration in Europe at Britain's lack of clarity over Brexit, however. European Commission President Jean-Claude Juncker said Wednesday morning that it is "highly probable" that Britain will not leave the EU on March 29 and showed his frustration at the proceedings. Speaking to Deutschlandfunk radio, he said, "When it comes to Brexit we're in God's hands. But even God has a limit to his patience." He reiterated that the EU won't renegotiate the Brexit deal. In her letter to the EU Wednesday, U.K. Prime Minister Theresa May said she intended to bring her Brexit deal back to Parliament next week despite the Speaker of the House John Bercow, ruling Tuesday that the deal would have to be substantially changed in order for her to be able to put it to MPs for a third time. The government could now look for ways around that decision. It hopes that Brexiteers will be encouraged to vote for the deal this time if faced with a potentially long delay. Frustration and disbelief at the uncertainty surrounding Brexit is not confined to the EU alone. Those closely following the latest twist in the long-running Brexit drama say it has reached tragic proportions. "Even Shakespeare could not have imagined a bigger drama," Holger Schmieding, chief economist at Berenberg Bank said in a note Wednesday, adding that U.K. Brexiteers had once set out to "regain control" but had instead given the EU more leverage to control what happens next.

Will the EU agree to a delay?

In a short statement Wednesday the EU Council President Donald Tusk said a short extension was possible but was "conditional on a positive vote in the House of Commons." Adding that the EU would not give up on apolitical solution "until the last moment," Tusk said he did not see any need at this point for an emergency EU summit but it was possible. That followed comments from the EU's chief Brexit negotiator Michel Barnier who said Tuesday that Europe must protect itself when considering a Brexit extension. At the forefront of the EU's concerns is preventing any disruption to European parliamentary elections between May 23-26. Berenberg's Schmieding said that the EU27 being "exasperated" with the U.K.'s dithering on Brexit was "understatement of the year." Still, the EU wants to avoid a "hard" Brexit (where no trade relationship with Britain is in place) and doesn't want to be blamed for causing a "no-deal" Brexit. That means that the EU could either endorse the U.K.'s request for a delay in principle on Thursday, or that EU could ask the U.K. to specify by 28 or 29 March "whether it wants to use the delay simply to finalize and ratify one of the three easy Brexit options, namely May's deal, an augmented customs union or full single market membership," Schmieding said. "The EU could then call a special summit at short notice to formally grant the Brexit delay request," he noted. If the U.K. said that it wanted a customs union or full single market membership this would require only limited changes, if any, to the Brexit deal (or 'Withdrawal Agreement', as it's officially known). But if the U.K. cannot endorse one of the three options on the table by 28 March, the delay would have to be much longer, Schmieding said.

How long could a delay be?