What does the Brexit deal say about the Irish 'backstop'?

One of the most difficult issues in Brexit talks was the Northern Irish 'backstop', an insurance policy to avoid a return to controls between the British province and EU-member Ireland which could threaten the 1998 peace accord which ended 30 years of violence.

Following are some of the key clauses from the Brexit deal's so-called "protocol" on Ireland and Northern Ireland.

TEMPORARY MEASURE (ARTICLE 1, P. 307)

The objective of the Withdrawal Agreement is not to establish a permanent relationship between the Union and the United Kingdom. The provisions of this Protocol are therefore intended to apply only temporarily, taking into account the commitments of the Parties set out in Article 2(1). The provisions of this Protocol shall apply unless and until they are superseded, in whole or in part, by a subsequent agreement.

FUTURE AGREEMENT (ARTICLE 2, P. 308)

"The Union and the United Kingdom shall use their best endeavours to conclude, by 31 December 2020, an agreement which supersedes this Protocol in whole or in part.

Any subsequent agreement between the Union and the United Kingdom shall indicate the parts of this Protocol which it supersedes. Once a subsequent agreement between the Union and the United Kingdom becomes applicable after the entry into force of the Withdrawal Agreement, this Protocol shall then, from the date of application of such subsequent agreement and in accordance with the provisions of that agreement setting out the effect of that agreement on this Protocol, not apply or shall cease to apply, as the case may be, in whole or in part, notwithstanding Article 20.

EXTENDING TRANSITION (ARTICLE 3, P.308)

The United Kingdom, having had regard to progress made towards conclusion of the agreement referred to in Articles 1(4) and 2(1) of this Protocol, may at any time before 1 July 2020 request the extension of the transition period referred to in Article 126 of the Withdrawal Agreement. If the United Kingdom makes such a request, the transition period may be extended in accordance with Article 132 of the Withdrawal Agreement.

SINGLE CUSTOMS UNION (ARTICLE 6, P.310)

Until the future relationship becomes applicable, a single customs territory between the Union and the United Kingdom shall be established ("the single customs territory"). Accordingly, Northern Ireland is in the same customs territory as Great Britain.

The rules set out in Annex 2 to this Protocol shall apply in respect of all trade in goods between the territories referred to in the second subparagraph, as well as, where so provided, between the single customs territory and third countries. With a view to ensuring the maintenance of the level playing field conditions required for the proper functioning of this paragraph, the provisions set out in Annex 4 to this Protocol shall apply. Where appropriate, the Joint Committee may modify Annex 4 in order to lay down higher standards for these level playing field conditions.

UK INTERNAL MARKET (ARTICLE 7, P.313)

Nothing in this Protocol shall prevent the United Kingdom from ensuring unfettered market access for goods moving from Northern Ireland to the rest of the United Kingdom's internal market.

SAFEGUARDS (ARTICLE 18, P. 328)

If the application of this Protocol leads to serious economic, societal or environmental difficulties liable to persist, or to diversion of trade, the Union or the United Kingdom may unilaterally take appropriate measures. Such safeguard measures shall be restricted with regard to their scope and duration to what is strictly necessary in order to remedy the situation. Priority shall be given to such measures as will least disturb the functioning of this Protocol.

REVIEWING THE BACKSTOP (ARTICLE 20, P.329)

"If at any time after the end of the transition period the Union or the United Kingdom considers that this Protocol is, in whole or in part, no longer necessary to achieve the objectives set out in Article 1(3) and should cease to apply, in whole or in part, it may notify the other party, setting out its reasons.

Within 6 months of such a notification, the Joint Committee shall meet at ministerial level to consider the notification, having regard to all of the objectives specified in Article 1.

The Joint Committee may seek an opinion from institutions created by the 1998 Agreement.

If, following the consideration referred to above, and acting in full respect of Article 5 of the Withdrawal Agreement, the Union and the United Kingdom decide jointly within the Joint Committee that the Protocol, in whole or in part, is no longer necessary to achieve its objectives, the Protocol shall cease to apply, in whole or in part. In such a case the Joint Committee shall address recommendations to the Union and to the United Kingdom on the necessary measures, taking into account the obligations of the parties to the 1998 Agreement.