WASHINGTON (AP) — House investigators are asking former national security adviser John Bolton to testify in their impeachment inquiry, deepening their reach into the White House as the probe accelerates toward a potential vote to remove the president.

Democratic lawmakers want to hear next week from Bolton, the hawkish former adviser who openly sparred over the administration's approach to Ukraine — in particular, President Donald Trump's reliance on his personal attorney Rudy Giuliani for a back-channel operation. Bolton once derided Giuliani's work as a "drug deal" and said he wanted no part...