WASHINGTON (Reuters) - Facing slumping poll numbers and a shakeup of his team, U.S. Republican presidential candidate Donald Trump takes a detour from the campaign trail this week to visit his golf resorts in Scotland. Trump leaves Thursday on a three-day trip centered on the grand reopening of Trump Turnberry, which the New York businessman bought in 2014 and renovated at an estimated cost of $290 million. He will also visit his other Scottish golf property in Aberdeen. His visit to Scotland, the birthplace of his mother, comes as Britain votes on Thursday on whether to remain in the European Union. Trump has said Britain would probably be better off if it left the EU. He will hold a news conference on Friday when he will doubtless be asked to respond to the vote. Trump’s trip abroad comes at an unusual time given the political calendar. With less than a month left until the Republican convention in Cleveland where he is to be formally nominated, Trump is lagging in fundraising and campaign organization and taking heavy fire from Democrat Hillary Clinton, his likely opponent in the Nov. 8 election. He is under pressure to adopt a more presidential demeanor and strengthen his campaign organization after a rocky period in which he criticized a U.S.-born federal judge as unfair because of his Mexican heritage and took fire for his response to the killing of 49 people at an Orlando, Florida, nightclub. Just this week, he fired campaign manager Corey Lewandowski at the urging of family members alarmed at the direction of his campaign. It also emerged that he had only $1.3 million in cash on hand at the end of May to fund his campaign, compared with  Clinton’s war chest of $42 million. His poll numbers have also dropped. After sealing the nomination seven weeks ago, Trump was basically tied in national polls with Clinton. But she has crept ahead in many polls in the past two weeks. Trump and his aides see the Scotland visit as a chance to showcase his far-flung business empire and job-creating abilities. Aides said the trip also reinforced his ancestral ties to Scotland and his love of family, with his children playing an important role in his business dealings. But many Republicans see Trump’s trip to Scotland as a waste of valuable time. “It has nothing to do with running for president,” said Republican strategist Rick Tyler, who was a spokesman for  former presidential candidate, U.S. Senator Ted Cruz of Texas. “It speaks to the non-seriousness of the campaign when you’re taking time off the campaign trail to leave the country for a place where there are no voters.” Trump’s golf properties are among his proudest business possessions and he is particularly proud of Turnberry, where the British Open has been played four times, including the famed “Duel in the Sun” in 1977 when Tom Watson edged Jack Nicklaus by one stroke. Limiting the trip to his golf properties means there are likely to be fewer chances for missteps like 2012 Republican nominee Mitt Romney’s gaffe-filled trip to London, Jerusalem and Poland four years ago. But it offers little chance for Trump to burnish his foreign policy credentials. “Traditionally, nominees take overseas trips to build their foreign policy chops,” said Republican strategist Scott Reed. Trump is not meeting British Prime Minister David Cameron, who has denounced Trump as divisive for his proposed Muslim ban and anti-immigrant rhetoric. 