In the interests of balance, this is also the truth but as opposed to your Cameron link (from 2015), it is from the Vote Leave website:
"Taking back control is a careful change, not a sudden stop - we will negotiate the terms of a new deal before we start any legal process to leave"
http://d3n8a8pro7vhmx.cloudfront.net...pdf?1463496002
And from the Conservative manifesto, that persuaded us to vote for their version of Brexit:
“We need to deliver a smooth and orderly departure from the European Union and forge a deep and special partnership with our friends and allies across Europe.”
It reiterated this need 8 times in the manifesto in order to secure enough votes from us to give them permission to negotiate the deal. We gave them permission on this basis.