Andrea Leadsom's Fresh Start website has a number of policy documents including one on trade (HERE) which they call green papers although they are not official government documents at all.
The trade one is interesting because it reviews several options like the Norway and Swiss models as well as trading on WTO rules, the back stop if we trigger Article 50 and fail to get a trade agreement with the EU settled in two years and the other 27 members do not give us an extension.
