The “Backstop” is essentially an insurance policy which both the EU and the UK government agreed upon to ensure that there will be no hard border between the Republic of Ireland and Northern Ireland if the issue of the border is not settled prior to the UK leaving the EU. In practical terms this would mean that until a permanent solution was found, Northern Ireland would remain in the Customs Union and to some degree, the single market, to avoid the need for a hard border on the island of Ireland.

As a result of the Good Friday Agreement in 1998, goods and people pass smoothly over the border between the Republic of Ireland and Northern Ireland – the only land border between the EU and UK. Prior to the Peace Treaty and the establishment of the Northern Ireland Assembly there had been a hard border in place and the presence of British troops. Aside for the added practicalities for trade between the Republic and Northern Ireland the symbolic presence of the current frictionless border is seen as a key achievement of the Good Friday Agreement and of the peace that the region has enjoyed since. The establishment of a hard border is seen by many to put that amity at risk by changing the nature of the agreement which brought about the peace. Furthermore, it would cause considerable upheaval to those who live close to the border and who are required to cross it regularly for work. 

The Backstop however has proved controversial with some and after the defeat of May’s Withdrawal Deal in the House of Commons on 15^th January 2019, it may be one of the features of the deal which is renegotiated. Brexiteers have two main issues with the Backstop as it is currently defined. Firstly, the Backstop would not have a defined end date so in theory Northern Ireland could remain in the temporary arrangement indefinitely.  This, they fear, would threaten the union of the United Kingdom (a major concern for the DUP too) as it would mean placing a hard border in the Irish Sea between Northern Ireland and the rest of the UK. Secondly, the terms agreed on the Backstop between the EU and the UK states that the Backstop can only be ended and a permanent solution enacted if both parties agree. This would mean the UK government could not end the Backstop arrangement without the agreement of the EU . 

The UK government may consider addressing the concerns the Brexiteers have over the Backstop to gain their support for May’s Deal and increase the chances of it passing through parliament next time. Any amendments to the Backstop will prove difficult for the Prime Minister however, due to several reasons. The backstop does not have a fixed end date by design because the whole point of the arrangement is to prevent a hard border in Ireland in the circumstances that a permanent agreement is not in place. To set a fixed end date to the Backstop agreement regardless of whether a permanent solution had been negotiated would defeat the point of its existence; a point reiterated by the Taoiseach (Irish Prime Minister) Leo Varadkar. Furthermore, the EU have shown little desire to renegotiate and they wish to ensure (without doubt) the prevention of a hard border in Ireland so the likelihood of May managing to persuade them to relinquish their control over this could prove challenging for the Prime Minister.

One solution the Prime Minister could opt for would be to keep the UK, as a whole, in a temporary regulatory agreement until a permanent solution could be found. This may have the backing of Labour MPs in Parliament; indeed, the Shadow Brexit Secretary Keir Starmer has acknowledged a Backstop may now be necessary due to the time restraints. As with all things Brexit however, this is a numbers game and such an arrangement would almost certainly result in an increase of Conservative MPs rebelling and voting against the Prime Minister.