Barack Obama: Donald Trump ‘woefully unfit to be president’

US president Barack Obama has declared Donald Trump “unfit” and “woefully unprepared” to serve in the White House.

In a searing denouncement, Mr Obama challenged top Republicans to drop their support for their party’s nominee, declaring: “There has to come a point at which you say, ‘enough’.”

The outgoing president’s blistering critique of his potential successor followed Mr Trump’s criticism of an American Muslim family whose son, a captain in the US Army, was killed in Iraq.