The Staggers 21 February 2017 When will Brexit actually happen? An Article 50 timeline Knowing the precise date of "Brexit Day" depends on the outcome of numerous untested laws Getty Sign UpGet the New Statesman's Morning Call email. Sign-up It’s the question on the lips of every Leaver - what is the date Brexit will finally happen? Article 50 is set to be triggered no later than March 2017. But reaping the changes of a full removal from the Union could take a lot longer. From rewriting legislation to negotiating the diverse interests of the European Union, Brexit is going to involve a lot of waiting. Will it still actually happen? There are a few things that could trip up an exit from the EU, however unlikely that might seem. The House of Lords, who have already started their voting process on Article 50 could potentially block the bill, but is more likely to threaten to block the bill in an attempt to leverage amendments - such as the position of EU citizens in the UK. Amendments that the House of Commons unilaterally failed to pass. Julia Rampen writes about every Remainer’s dream - some sort of backdoor challenge that The People’s Challenge, a campaign group, believe exist. According to the founders, it is entirely reasonable to revoke Article 50 at the end of negotiations, if Brexit is not a done deal. Okay, so if it does happen, when? Prime Minister Theresa May has stated that she wants to trigger Article 50, a clause of The Lisbon Treaty in March 2017, which gives a country two years to decide the terms of the departure. This puts Brexit approximately happening in Spring 2019, providing all the negotiations are complete in that estimated time period. But in effect, this only means Brexit will begin in Spring 2019. The results of leaving the EU, such as all the changes to laws that were once determined by the Union, will take years. As for the economic promises made by the Leave campaign, they may take even longer (if they even exist). This leaving process will begin with The Great Repeal Bill - an as of yet unpublished bill created in order to help a transition from EU laws to UK laws. This bill essentially states that the authority of EU laws will be revoked, and “where practical” will be transposed to domestic laws, able to therefore be adapted as appropriate for the UK. A telling part of the Government's briefing on The Great Repeal bill is the quote that adapting EU laws for domestic use “may require major swathes of the statute book to be assessed to determine which laws will be able to function after Brexit day” (Brexit Day not being a national holiday of mourning, but the day the UK officially leaves the European Union). This is where the core issue lies, that in theory we could have left the EU by 2019, but in practice, the changes that will invoke won’t be in play for years. The main ambiguity with Brexit lies in the fact that these are relatively new and untested laws. Since it was written in 2009, Article 50 has never been invoked, so the estimation of a two year negotiation period is largely a theoretical one. Various MPs such as Philip Hammond, Chancellor of the Exchequer, have noted that the process would likely exceed the two year framework - something that could be dangerous for the prosperity of the UK. › The 43 people Donald Trump listens to Subscribe For more great writing from our award-winning journalists subscribe for just £1 per month!