Almost all parents and pregnant women in China, Vietnam and the UK are exposed to “aggressive” formula milk marketing campaigns that breach global rules set up after scandals more than 40 years ago, according to a new report.

The marketing techniques can push women away from breastfeeding and include everything from giving free samples to executives setting up or joining "mums' groups" on popular messaging apps, the report from the World Health Organization (WHO), Unicef and M&C Saatchi said.

Health workers are also targeted with...