Sir Martin Sorrell says Google must 'place ads in the right way'

Marks and Spencer has become the latest firm to pull its online advertising from Google's platforms over fears it is appearing next to extremist content.

Sir Martin Sorrell, the head of WPP; the world's largest advertising firm, told the Radio 4's World at One that Google must now demonstrate they are more in control "of the places where the adverts appear".

Sir Martin called for a "white list of appropriate sites and a black list of inappropriate sites" where advertisers' content "would not appear on the black list".