The world's largest media buying firm has urged Google to apologise to consumers and advertisers over its failure to remove videos by terrorist-linked organisations.
GroupM, which is part of advertising giant WPP (Frankfurt: A1J2BZ - news) , said it would also write to clients to ask if they want to pull advertising from Youtube after MPs (BSE: MPSLTD.BO - news) said Google was "still profiting from hatred".
Yvette Cooper MP, chair of the Home Affairs Select Committee, said that Google's failure to remove the videos by was "frankly astonishing"
On Tuesday, the Home Affairs Select Committee summoned bosses from Google, Facebook (NasdaqGS: FB - news) and Twitter (Frankfurt: A1W6XZ - news) , to question them about the action the web giants were taking to remove hate speech from their platforms.
At that appearance, the committee drew attention to videos by National Action, a proscribed organisation which the Government has said is linked with terrorism.
Nevertheless, videos from the group remain on YouTube. The committee said it had found one in which masked men shout "they fear us because they think we will gas them, and we will."
At Tuesday's hearing, the committee also raised the issue of adverts automatically being put next to hate videos.
Reports on Thursday and Friday in the Times found that government and major brand advertising was still being hosted next to hate videos.
As a result, the government, along with commercial organisations including the Guardian and French advertising giant Havas (LSE: 0MGT.L - news) , suspended advertising with Google. Google was summoned to appear in front of Cabinet Office ministers today.
In today's letter, Ms Cooper also wrote:
"Google is the second richest company on the planet. The lack of effort and social responsibility it is showing towards hate crime on YouTube is extremely troubling.
"It is inexplicable to us that Google can move very fast to remove material from YouTube when it is found to be copyrighted, but that the same prompt action is not taken when the material involves proscribed organisations and hateful and illegal content."
A Google spokesman said: "We have strict guidelines that define where Google ads should appear, and in the vast majority of cases, our policies work as intended, protecting users and advertisers from harmful or inappropriate content.
"We accept that we don't always get it right, and that sometimes, ads appear where they should not. We're committed to doing better, and will make changes to our policies and brand controls for advertisers."