Boris Johnson's pro-EU column published for first time

Before Boris Johnson embraced Britain's "leave" campaign and then became the country's foreign minister, he wrote an unpublished newspaper column arguing the case for keeping the U.K. inside the European Union.

The Sunday Times published Johnson's pro-EU column, which outlines his fears about the economic shock that leaving the EU would cause and the value of keeping access to the EU's single market of 500 million people.

Johnson writes "the membership fee seems rather small for all that access."

The column was written days before Johnson made up his mind to join the "leave" campaign and argue that Britain should withdraw from the 28-nation bloc. Britons decided to do just that in a June 23 vote.

Now Johnson's a key figure in the Conservative government taking Britain out of the EU.