It is being claimed that Boris Johnson wrote an article urging the UK to stay in the EU, two days before deciding to spearhead the leave campaign.
The British Foreign Secretary apparently used a newspaper column to say withdrawing would trigger an economic shock, Scottish independence and Russian aggression.
Sky News chief political correspondent Jon Craig says a new book contains the allegations:
The article was never published, but Boris Johnson composed it just 2 days before making this announcement in February: