Donald Trump's opponents have been calling for Barack Obama to come back on Twitter as the scandal surrounding the US President continues.

Trump faces fresh crisis after his son and campaign leader, Donald Trump Jr, released a tranche of emails detailing his correspondence with Russian contacts last June.

The email dump is the latest embarrassing revelation for Trump, who has faced constant scrutiny over his relationship with Russia before and during last year's election.

Now his opponents are calling for some very drastic action - the return of Trump's predecessor to save America.

Sadly for Obama fans, it's actually impossible as Obama served two terms of office, and so cannot run for the White House again.

But that hasn't stopped his supporters dreaming, as the following tweets show.