The Prime Minister’s Office said two new frameworks would provide "a new and improved way for the public sector to buy communication" and would allow the Government "access to a wide range of the best creative agencies".
The new frameworks will replace existing government contracts for creative solutions, strategy, planning and events.
The Government said it had developed the new contracts in consultation with the comms industry and trade bodies.
Aiken said: "We would particularly like to thank the IPA, CIPR, ISBA, DMA, PRCA and the wide variety of agency representatives for their feedback and guidance. We will continue our engagement with industry and the government communication profession to ensure the proposed arrangements work well for everyone."
The CIPR welcomed the reformed contracts and said they would "drastically reduce" the length of the application process, making it easier for small consultancies to bid.
The body also said agencies would no longer be required to have delivered previous public sector work and that bids would be welcomed from across the UK.
Rob Brown, CIPR president, said: "Tendering for public sector business has historically been a major cost for large agencies and a barrier to smaller and newer suppliers. These new arrangements change that overnight."
Brown added that he hoped other public sector bodies, such as the BBC and local government, would take the government’s lead and simplify their processes.