High tech camera collars give a birds eye view of polar bears struggling to find food on the shrinking arctic ice. And coming up in the sport on bbc news, can liam brodie recover from a difficult start in great britains opening davis cup rubber against spain in marbella . Good afternoon and welcome to the bbc news at one. Theresa may is coming under increasing pressure to spell out what she hopes to achieve from the brexit negotiations, including whether britain should remain part of the Customs Union after it leaves the eu. Some leave supporting conservative mps have urged the Prime Minister to be more specific about her priorities for future trade deals. Downing street says mrs may has an open mind to the kind of customs arrangement the uk should pursue. Speaking to our Political Editor laura kuenssberg, theresa may said her visit to china will help boost British Trade prospects. This trip is an example of Global Britain. Its about britain getting out around the world, and, yes, enha