Johnson floated his “Britzerland” idea this week in Weltwoche, a right-wing weekly German-language magazine based in Zurich.
The Tory politician, who has made known his distaste for Britain’s involvement in the EU, tells the magazine the two countries could found a new grouping.
It would be a fair trade area outside the EU that could trade with the EU under terms it helps shape but would otherwise be not involved in the “integrationist Brussels concept,” the magazine reported on Thursday.
Switzerland and Britain have every interest in creating a new area separate from the EU, Johnson said.
Other countries, notably Norway and Sweden, could join the area, he said.
Johnson has gone on record as saying it would not be the end of the world if Britain left the EU.