You believe there was a plan ?
I'm certain there wasn't.
The last time British voters were formally consulted on continued membership of what was then called the Common Market, in 1975, mainstream politicians of the major parties joined forces with experts and establishment figures to persuade Britons that leaving was too great a risk. The “In” campaign prevailed.
This time, 41 years later, an almost identical strategy was adopted by the Remain camp. The Conservative prime minister, David Cameron, led the effort, with the notional support of the Labour Party leader, Jeremy Corbyn, and a phalanx of heavyweight economists and world leaders (including, most theatrically, President Obama). Open letters signed by dozens of accomplished figures in their respective fields urged the voters to shun the perils of Brexit.
In 1975, the British people deferred to such authorities. In 2016, they ignored them.
http://www.nytimes.com/2016/06/27/opinion/david-camerons-brexit-bust.html