‘I'm in' was launched at the beginning of the year with the primary goal of keeping up the momentum generated by the Make Poverty History campaign.
M&F has been hired to work on ‘word-of-mouth and face-to-face activity', said Oxfam PR co-ordinator Katie Abbotts.
She declined to reveal further details of the campaign, but said it would be launched in London in November before moving to other cities.
M&F managing director Judie Flexen said: ‘All I can say about it at this stage is that there are some exciting and highly creative plans - watch this space.'
Band & Brown Communications continues to handle traditional PR activity for ‘I'm in' (PRWeek, 13 January).
B&B's brief, which focuses on media relations, targets those inspired by Make Poverty History, such as members of the public who purchased wristbands.
The agency has been approaching a broad range of media to emphasise the different ways in which support can be pledged.
When B&B was hired, it was the first time the international aid charity had taken on external PR help for a specific campaign.
The competitive pitch for the project won by M&F was overseen by the PRCA's PReview service.