Parliamentary approval of the final terms for leaving the EU

Thank you for contacting me about parliamentary approval of the final terms for leaving the EU.
Both Houses of Parliament will have a vote on the final deal as soon as it is agreed with the EU and before the European Parliament votes on it. The Constitutional Reform and Governance Act 2010 will also require the treaty made with the EU to be put before Parliament and the treaty will only have effect if Parliament does not resolve against it. 
Once the endorsement of Parliament has been secured, a Bill will be introduced to implement the withdrawal agreement into UK domestic law. This includes the agreement reached on citizens' rights, any financial settlement and the implementation period. This means that Members of Parliament in the House of Commons and Peers in the House of Lords will be able to debate, scrutinise and vote on the final agreement made with the EU. There can be no doubt that Parliament will have a full opportunity to have its say on the final agreement.
A minister will also make a statement to Parliament in the event that MPs reject the deal or if no deal is reached with the EU by 21 January 2019 or if the Prime Minister announces by that date that no deal can be reached. There will be a vote on a motion on the Government's proposed next steps in each of these circumstances so that Parliament can have its say.
Article 50 of the Lisbon Treaty has been invoked and there is a two year period in which to agree a withdrawal deal. EU law is clear that if a withdrawal agreement is not reached by the end of this period, the withdrawing country will simply leave the EU without any deal. 
It is also not within the power of the UK Government to unilaterally extend the negotiating period. EU law states that this period can only be extended with the unanimous agreement of the remaining member states of the EU and it may well not be in the gift of the Government to fulfil it. I am confident that a deal will be reached, however, and it is unlikely that any of these situations would arise.
Thank you again for taking the time to contact me.