John Legend wants First Lady to intervene, after Donald Trump calls singers' wife 'filthy mouthed'

President Donald Trump is criticising musician John Legend for not playing a role in passing criminal justice reform following a TV special on the subject in which the star appeared.

Trump also says he hasn't gotten enough credit for signing a law instituting some reforms. The law reduced mandatory minimum sentences, among other measures.

In a series of tweets late yesterday and early today, Trump called Legend "boring". He also said Legend's wife, model Chrissy Teigen, is "filthy mouthed".

Legend responded by saying Trump is hungry for praise and asked Trump's wife Melania to step in.

Teigen wrote she didn't appear on the special and used crude language to describe Trump.

Chrissy Teigen, John Legend and Donald Trump. Source: Associated Press