The postal operator is increasing its promotional investment in the service, which has signed up 100,000 customers since its January launch, and will commit a significant slice of its £13m marketing budget to it.
Simon Carter, head of marketing at the Post Office, said that HomePhone would eventually receive more promotional spend than any of its other products, as it strives to meet a target of 1m customers in five years.
The campaign running this summer will include TV and radio ads by Publicis, and direct activity including in-store promotion across its network of 15,000 Post Offices. All activity will feature the Post Office's animated ant characters.
The HomePhone service is based on a single tariff, which it claims is between 10% and 20% cheaper than BT.
The Post Office's entry into the phone market has angered BT. The communications giant has had a number of complaints about HomePhone's launch advertising upheld by the Advertising Standards Authority.
The Post Office's planned launch of a broadband internet service later this year is expected to increase the tension between the two firms.
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