The European Union has offered U.K. lawmakers more time to agree on a Brexit plan. Why is the extension needed?

Theresa May’s plan to exit the European Union has failed to pass the British Parliament three times. Some have blamed party disunity or May’s mishandling of this issue.

However, a key reason for the failure – and the one that hasn’t received a lot of attention – is the so-called “Irish backstop.”

The EU requested, and May agreed, to the backstop in order to protect the Good Friday Agreement, which relies on both countries being in the EU. A hard border would require checkpoints and other infrastructure that could become physical and symbolic flashpoints for Nationalists who support a united Ireland.

A new analysis that we have just completed shows that Parliament’s objection to the backstop amounts to an implicit rejection of the Good Friday Agreement, the agreement that brought the end of armed conflict in Northern Ireland. Indeed, the reasons Parliament objects to the backstop are exactly what made the peace agreement work.

How does the Good Friday Agreement factor in?

The Good Friday Agreement, signed 21 years ago, didn’t solve the geopolitical dispute at the heart of the decadeslong conflict in Northern Ireland: Should Northern Ireland be a part of the U.K. or the Republic of Ireland?

Instead, the agreement found a creative way around the issue by allowing a form of co-sovereignty. The Good Friday Agreement allowed people in Northern Ireland to identify as Irish, British, or both, and to hold a passport from either or both countries.

As a consequence, people and goods currently cross the border without stopping.

As Jonathan Powell, one of the key negotiators for the British in the peace talks, argued, having a soft border “meant the issue of identity was really removed from the table.” This was no small feat in a place where one’s identity as Irish/Nationalist or British/Unionist historically shaped where you lived, who you married and where you worked.

But then Brexit came along and challenged core elements of the Good Friday Agreement.

When the U.K. eventually leaves the EU, the border between Northern Ireland and the Republic of Ireland will require a border apparatus to check passports of visitors, track the origin and quality of goods, and collect appropriate taxes or customs.

Recreating border infrastructure risks undermining the extensive economic integration that has developed between Ireland and Northern Ireland. It also upends the ability of Nationalist citizens of Northern Ireland – people who advocate for a united and independent Irish state – to see themselves as Irish while living in Northern Ireland. The British government has already announced, for example, that after Brexit it will no longer treat people born in Northern Ireland who claim Irish citizenship the same as citizens of the Irish Republic when it comes to certain rights and benefits that are guaranteed to EU subjects living in the U.K.

For the Nationalist population in Northern Ireland, this means a key provision in the Good Friday Agreement – the right to choose your identity and to carry dual passports – no longer applies.

Why was the backstop controversial?

As scholars of Northern Ireland, we are keenly interested in how Brexit will affect the peace. We just returned from the annual International Studies Association meeting where we presented a paper on how members of Parliament were discussing Brexit’s impact on Northern Ireland.

In particular, we focused on three debates held over eight days between December and March in the House of Commons on the prime minister’s withdrawal deal.

Using the Hansard record of parliamentary debates, we cataloged the objections members of Parliament made about May’s Brexit deal. While the primary objection was trade, the backstop received the second highest number of objections.

Theresa May staunchly supported the backstop in all three parliamentary debates. Her grounds were that it would maintain Northern Ireland’s place in the union by preserving its peace deal and providing for the interests of the majority of its residents who do not want a hard border.

She referred to the provision of the Good Friday Agreement that allows the people of Northern Ireland to choose to leave the union and form a united Ireland.

If “this House cares about preserving our Union, it must listen to those people, because our Union will only endure with their consent,” May said.

However, many members of Parliament who opposed May’s plan saw it another way.

They argued that the backstop represented a threat to the union of Great Britain and Northern Ireland because it would treat Northern Ireland differently than the rest of the U.K. by leaving it subject to EU regulations.

Dozens of MPs referred to the risk of breaking up the U.K. As Conservative Party MP Priti Patel said during the Jan. 10 debate, this would be the “first time in modern history a U.K. government negotiate[d] to cede part of our country to a foreign power.”

Throughout the three debates, the peace process was not central for most MPs. Indeed, while the backstop received 795 mentions in the three debates we analyzed, “Good Friday Agreement” and “Belfast Agreement” – two terms that describe the same accord – combined received only 90. This indicates that discussion of the backstop was not commonly tied to the agreement.

When MPs did mention the agreement, and what the rejection of the backstop would mean for it, they primarily defended only one side of the historical conflict – the side of the Unionists who support Northern Ireland’s political connection with Great Britain.

Several reasons explain why.

A one-sided debate

First, although the largest Nationalist Party in Northern Ireland, Sinn Fein, fields candidates for parliamentary elections, the party’s seven MPs refuse to take their seats because they do not acknowledge the sovereignty of the U.K. in Northern Ireland.

With the Nationalist side not represented in Parliament, the Unionist position became, by default, Northern Ireland’s position.

Second, after May lost her majority in the 2017 elections, she was forced to enter into what’s called a “confidence and supply agreement” with the Democratic Unionist Party’s 10 MPs in order to govern. The DUP views a united Ireland as an existential threat to its Protestant, British identity. It has become the largest party in Northern Ireland since the Good Friday Agreement, though it represents only about 36% of voters there.

In the agreement with May, the DUP pledged to support May’s positions on major policy decisions. In return, May’s party renewed its commitment to preserving the union between Northern Ireland and Great Britain and delivered more than £1 billion in funding.

May’s Conservative and Unionist Party is dependent on DUP support to stay in power, but the DUP has never supported the Good Friday Agreement. In fact, it was the only party to withhold support for the agreement in 1998. It has spent most of the time since trying to rewrite or undermine the agreement.

The DUP did agree, as part of the agreement with May, to “adhere fully” to its commitments in the Good Friday Agreement, but the agreement provides no benchmarks for what support should entail.

And, in each of the debates we analyzed, the DUP breaks this pledge by strongly opposing the withdrawal deal. Not surprisingly, they see the backstop as a threat.

As DUP MP Paul Girvan said in the December debate, “What was not achieved by” armed Nationalists during the conflict “has been achieved by bureaucrats in Europe with a pen.”

These debates reveal that many in Parliament seem willing to reject the very arrangement that made peace in Northern Ireland possible.

As Conservative MP Stephen Crabb noted in the House of Commons in January, the challenge of “squaring Brexit against the Northern Ireland peace process was always going to require incredibly sensitive handling and … compromises were always going to be inevitable.”

Our analysis reveals that it’s not clear that Parliament has the cohesion or commitment to do the hard work that is required to preserve the agreement.

Carolyn Gallaher is affiliated with Latin American Working Group Education Fund, where she serves as the Chair of the Board. The position is not funded and the organization is a non-profit.

Kimberly Cowell-Meyers does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.