Watch: 'I charge you with hypocrisy' - Piers Morgan and London's mayor clash over 'Trump Baby' blimp

London Mayor Sadiq Khan has come under fire for his approval of a blimp featuring US President Donald Trump dressed as a baby.

Good Morning Britain host Piers Morgan challenged Mr Khan over the decision, suggesting the mayor had approved of the blimp due to personal animosity towards the US President, the Daily Mail reports.

Mr Morgan asked if Mr Khan would have approved a large black blimp featuring former US President Barack Obama, or an image depicting the London mayor as a pig - something which would offend his Muslim faith. 

"My views are irrelevant. The issue is 'Do they have freedom to protest, freedom to assemble and should they be allowed to do so? If it's peaceful and it's safe, they should," Mr Khan repsonded.

"Look - I can't be the censor. It's not for me to decide what's in good taste or bad taste."

The six-metre high blimp, dubbed 'Trump Baby', has been granted permission to fly above Parliament Square for two hours on Friday morning.