Biden retains front-runner position for presidential nomination

Joe Biden has cemented his position as front-runner in the democratic race to take on president Donald Trump in November’s White House election.

The former vice-president won Michigan, the biggest prize of primary voting on Tuesday, extending his lead over main rival senator Bernie Sanders.

Five other states – Washington, Missouri, Mississippi, Idaho and North Dakota voted on Tuesday.

Mr Biden also swept aside Mr Sanders in Missouri, Mississippi and Idaho.

It was unclear if Mr Sanders would fight on until the party convention in July.