The Coalition Government is considering widening the COI's role by using the body as a portal for all comms contracts, including quangos of all sizes and a variety of funding models.
Currently about 50 per cent of Government campaigns go through the COI.
One agency source said: 'Any public sector body that currently doesn't go through the COI may have to use it as a contract portal. The COI's role is going to be to drive efficiency and ensure the most successful procurement.'
Another PR agency boss said the COI had been 'fighting this battle for 12 to 18 months' and was now chiming with the Government's wishes to more carefully scrutinise marketing spend.
COI director of news and PR Neil Martinson would not comment on whether the COI's remit would increase.
But he said: 'The thing to look at is what cabinet ministers are saying and they are calling for a greater use of shared services.
'It's part of that picture. The position is that departments are being told they have to use a recognised framework.'
But another source suggested the plan could be rejected by Government departments: 'If (Cabinet Office minister) Francis Maude wants to force the departments to buy under COI supervision, he'll have a fight on his hands.'
The COI is also looking at ways to support more integrated PR and advertising campaigns, revealing that an announcement will be made 'in due course'.
A COI spokesman said: 'We are looking at the relationship between owned, earned and paid-for media to deliver more effective campaigns and significantly lower costs.'
However, the COI denied suggestions the review would result in the bringing forward of an agency roster repitch, due to take place in 2013.
UNDER THE COALITION
The Government has implemented a freeze on new government advertising and marketing spend, which will end in March
The Government will continue to commission comms, but only where there is an essential need
Last month, it emerged the COI is considering a wave of redundancies