The newly created single brief covers four of the department's major comms programmes - Smokefree/Tobacco Control, the Change4Life obesity campaign, Older People and Younger People.
The DH said its approach to agency use had been overhauled as a result of a number of current PR contracts coming to an end.
But the change in strategy also follows the publication of a three-year social marketing strategy, Changing Behaviours, Improving Outcomes.
The document states that the department has been overdependent on single-issue campaigns, 'missing the opportunity to "ladder" people up from successfully tackling one behaviour, to changing others'.
The strategy document states: 'Too often in the past we have held separate conversations with the same people, one day talking to them about their diet, the next about their alcohol consumption, without recognising that poor diet and drinking at higher risk levels are linked behaviours in an unhealthy lifestyle, reflecting deeper and shared problems.'
The DH is building on the Change4Life comms model, whereby a 'single trusted brand' delivers comms on multiple topics.
But senior agency figures questioned the new strategy. One senior source at a major international agency said: 'It is unlikely that any one agency would have the depth of expertise and range of skills to be able to handle this brief effectively.
'The Government has failed to make a significant impact with consumers on key public health issues over the past couple of years.
'It should be looking to be more targeted and sophisticated in its approach to consumers, not consolidating multiple complex issues into one brief.'
Sarah Wrixon, MD of Salix Consulting, added: 'It does seem sensible to take a more holistic view towards public health issues.
'However, if the DH is to move to an enhanced version of Change4Life, the obvious question to ask is what return has it seen on this multi-million-pound investment? Where is the evidence that it is working?'
The news comes as former Department of Health comms chief Sian Jarvis takes a role at Asda to oversee its PR and lobbying.
The DH refused to provide information on the agencies currently used. However, the following have recently been rostered and could stand to pick up the brief:
Freud Communications: Freuds has been handling the DH's flagship anti-obesity drive Change4Life since 2008. It is currently worth between £40,000 and £45,000 per month to the agency.
Consolidated: The agency is currently working on a project for DH called My Health London, and has previously handled the DH's swine flu vaccination campaign.
Blue Rubicon: The agency has worked on tobacco control campaigns.
£340k - Budget available for this PR brief from December to next March
£20-50k - Additional budget for 'emergency work', such as pandemic flu
20 - Number of social marketing campaigns the DH backed in 2009
40% - Cut to the DH's budget for marketing activity this year
Source: Department of Health