LONDON : British Prime Minister David Cameron was to jet off to Portugal on Saturday for his summer holiday, Downing Street said. However, the premier will be back in Britain for the closing ceremony of the Glasgow 2014 Commonwealth Games on Sunday, and then travel to France and Belgium on Monday to take part in ceremonies to commemorate the centenary of the outbreak of World War I, his office said. The Conservative leader will then rejoin his wife Samantha and their children Nancy, Elwen and Florence for the remainder of their summer break.