The on-off visit of Donald Trump to the UK is happening - but that doesn't mean the controversy has stopped.

Thousands are taking to the street to condemn the arrival of the leader of the free world, while a giant baby blimp has mocked the US president from the sky.

Any yet Britain has entertained some equally controversial world leaders before him.

So why are people so unhappy this time and why didn't Mr Trump get the state visit treatment Britain offered to Robert Mugabe?