Britain’s parliamentary system allows the governing party to replace its leader — and therefore the prime minister — without holding a national election. "Andy Burnham is the least scrutinized incoming U.K. Prime Minister of recent times," Alan Mendoza, executive director of the London-based Henry Jackson Society, told Fox News Digital. "He wasn’t even a candidate at the last general election." So, I think for all of those reasons, there ought to be a general election and a fresh mandate." Asked in June what he knew about Burnham, Trump said, "I don’t know, I think I see that he was, I guess, the mayor of a town."