BRITAIN’S post-Brexit transition period could effectively last up to five years, Greg Clark, the UK Business Secretary, has signalled as Tory tensions rise ahead of Theresa May’s plan to present a tweaked version of her contentious customs arrangement plan to senior colleagues this week. . http://www.heraldscotland.com/news/16208132.Clark_admits_it__39_s__quot_possible_quot__customs_infrastructure_not_ready_until_2023/?ref=rss