Union Unite’s attempt to launch an online marketing offensive against Marks & Spencer appears to have been thwarted by Google.

The union revealed this morning that it had placed an advert on search engine Google, which should have displayed in the sponsored links if consumers searched on terms including “M&S” and “M&S Foods”.

The online advert was meant to direct Google users to Unite’s campaign web page, which provides details of what Unite claims is “widespread discrimination in the treatment of workers in the UK meat supply chain”.

However, Retail Week was unable to view the advert through Google when searching on any terms relating to the retailer.

Google reserves the right to disapprove any keywords that advertisers add to campaigns and trademark owners can also complain to Google.

On Google’s site, it states that it will investigate complaints and may require the advertiser to remove the trademarked term from the ad text or keyword list and will prevent them from using the trademarked term in future.

A Google spokesperson said that it does not comment on individual cases.