30.Some litigation procedures under the withdrawal agreement The withdrawal agreement provides for a transitional period until 31 December 2020, during which time the UK will remain in the single market to ensure the smooth running of trade until the agreement on a long-term relationship is agreed upon. If no agreement is reached by then, the UK will leave the single market without a trade deal on 1 January 2021. The withdrawal agreement is closely linked to a non-binding political declaration on future relations between the EU and the UK. Immediately after the announcement of a revised withdrawal agreement on October 17, 2019, Labour, the Liberal Democrats and the DUP said they could not support the new agreement.  On 15 January 2019, the House of Commons voted with 230 votes against the Brexit withdrawal agreement, the largest vote against the British government in history.  The government may survived a vote of confidence the next day.  On March 12, 2019, the House of Commons voted 149 votes against the agreement, the fourth-biggest defeat of the government in the history of the House of Commons.  A third vote on the Brexit withdrawal agreement, widely expected on 19 March 2019, was rejected by the House of Commons spokesman on 18 March 2019, on the basis of a parliamentary convention of 2 April 1604, which prevented British governments from forcing the House of Commons to vote several times on a subject already voted on by the House of Commons.    An abbreviated version of the withdrawal agreement, in which the annex political statement had been withdrawn, consisted of the test of “substantial amendments,” so that a third vote was held on 29 March 2019, but was rejected by 58 votes.  While the previous “backstop” kept the UK in a customs union with the EU, the new AV sees that the whole of the UK (including Northern Ireland) is leaving the EU customs union. From a legal point of view, Northern Ireland remains a part of the British customs territory. Northern Ireland will be included in the UK`s free trade agreements. The agreement covers issues such as money, citizens` rights, border agreements and dispute resolution.