Opinion studies in Britain show almost equal support for staying and remaining in the European Union ahead of a vote on the issue Thursday. British Prime Minister David Cameron made an appeal Tuesday for voters to support staying in the 28-member EU. “Brits don't quit,” said Cameron in remarks outside his Downing Street office. He especially appealed to older voters who have been less supportive of the campaign to stay in the EU. “It will just be you in that polling booth. Just you, taking a decision that will affect your future, your children's future, your grandchildren's future.” He added: “They can't undo the decision we take. If we vote out, that's it. It's irreversible.” Cameron also spoke to Britons who did not vote for him and may not agree with his policies.