The first phase of the £60m Government Secure Intranet (GSI)project has been completed more than a year ahead of schedule, giving 350,000 public sector workers from more than 150 government departments access to a common network.
Networks company Energis said it completed the government staff migration to the new GSI last month, 15 months ahead of its deadline.
The value of the original £40m contract with Energis has increased by 50% to cover the need for increased capacity, including a doubling of bandwidth.
The GSI, which is already handling more than one million e-mails a day, will act as a common communications network for 154 central government departments, with comprehensive security for information sharing and 100% availability for all users.
It is designed to offer a technical platform for more joined-up government, allowing users to share data with any other organisations in the GSI community via its peer-to-peer infrastructure.
The GSI also has peer-to-peer connections into the Criminal Justice Exchange, Ministry of Defence, NHSNet, EU Council of Ministers and Testa European government network, allowing sensitive information to be exchanged securely.
The network is also voice-ready, allowing government departments to plan ahead for the future roll out of VoIP systems.
A spokesman for government agency OGCbuying.solutions said, "We are very pleased with the work, and the teamwork in particular, that has contributed to getting this project successfully completed ahead of deadline. GSI is now the primary information sharing hub for the entire public sector."