WASHINGTON (AP) — The Trump administration plunged into an extraordinary showdown with Congress Thursday over access to a whistleblower's complaint about reported incidents including a private conversation between President Donald Trump and a foreign leader. The blocked complaint is both "serious" and "urgent," the government's intelligence watchdog said.

The administration is keeping Congress from even learning what exactly the whistleblower is alleging, but the intelligence community's inspector general said the matter involves the "most significant" responsibilities of intelligence leadersh...