What Happened

With just two months left before the United Kingdom is scheduled to leave the European Union, the British House of Commons has instructed Prime Minister Theresa May to renegotiate parts of her Brexit deal. On Jan. 29, British lawmakers approved a proposal to revise the Irish backstop, a safeguard measure designed to ensure the border between Northern Ireland and the Republic of Ireland remains open after Brexit. In addition to rejecting a key part of the divorce agreement May negotiated with the European Union in late 2018, lawmakers voted against plans to delay Brexit if no deal is reached and shunned proposals to give Parliament control over the legislative agenda on Brexit. Parliament also stated its opposition to leaving the European Union without an exit agreement, though this was largely a symbolic declaration.

What Happens Now

These votes in the Commons will impel May to ask Brussels to renegotiate the Irish backstop, which would keep the United Kingdom in a customs agreement with the European Union until a permanent solution for the Irish border is found. To appease her country's lawmakers, May could ask for the backstop to be done away with. Alternatively, she could request a time limit for the backstop or push for a provision granting London power to unilaterally withdraw from the proposed temporary customs agreement. However, the European Union has repeatedly said that the backstop cannot be renegotiated, and EU leaders are unlikely to change their minds.

The European Union would agree to eliminate the backstop if London asked to remain in the customs union. But while Labour, the main opposition party, supports this idea, most members of May's Conservative Party have rejected the notion. May could opt for a less radical approach, such as requesting additional reassurance that the backstop is not meant to be used. However, the hardline Brexiteers within May's party were unconvinced by these reassurances the last time the European Union provided them.

In the likely event that May fails to sufficiently rework the backstop, she could call for another vote on her withdrawal agreement in the hopes that fears of a no-deal Brexit will compel lawmakers to support it. However, her first vote on the deal lost by a historic 230 votes, making it highly unlikely that any similar proposal will pass.

Why It Matters

The recent votes in the House of Commons send a clear message that the majority of British lawmakers oppose the Irish backstop. But even if the Commons are able to unite around a plan for Brexit, such a solution would still require EU approval. Parliament may have voted against delaying Brexit, but that scenario is still on the table provided London is able to convince Brussels that it will use the extra time wisely. If May's efforts to renegotiate the backstop fail and her government decides to ask Brussels to delay Brexit — which the European Union's member states would have to unanimously approve — London will have a number of options open to it. May's government could, for example, soften its stance on the customs union and single market, use the extra time to hold early elections or, in a dramatic but unlikely turn of events, hold a second referendum.