[nomadking]

Originally Posted by 1andrew1

Getting a deal is not easy as you need to get the WAB done first and that's not proving easy!

You don't need to do anything first. Any WA is optional. According to Article 50, it is up to the EU to try and negotiate one.
Link

About article 50
Article 50 sets out the process for a member state to leave the EU. It is up to the country in question to withdraw “in accordance with its own constitutional requirements”. Once triggered, article 50 allows for two years of negotiations, although this can be extended unanimously by the European Council.
Although the aim is to come to a deal, it is also possible there is no agreement at all.
Two agreements
The EU and the UK have two years to negotiate a withdrawal agreement setting out the arrangements for how the country will leave the Union, while “taking account of the framework of the future relationship with the Union”. The arrangements setting out the framework for future relations will be part of a separate agreement, which could take considerably longer to negotiate.

Article 50.2

A Member State which decides to withdraw shall notify the European Council of its intention. In the light of the guidelines provided by the European Council, the Union shall negotiate and conclude an agreement with that State, setting out the arrangements for its withdrawal, taking account of the framework for its future relationship with the Union.