The charity expects the successful agency to gain national coverage for the event, bring on board a high-profile, 'mum-friendly' celebrity to engage and support the campaign, and promote baby swimming lessons via partner company Water Babies.
According to Tommy's, the target audience is mums with children aged zero to four, Water Babies' clients, dads, grandparents and carers.
Budget for the work is set at £50,000-£70,000, and search for the agency is being handled by Tommy's senior marketing manager Siobhan Gray.
Interested parties are being asked to send initial credentials before 23 December. The successful agency in the process is scheduled to commence work on 13 February.