The first phase, completed last week, lets the government sharing information across government departments and between the central government and other UK and European government bodies.

GSi was first established in 1997, and provided basic messaging and Internet access. The new GSi will add centralized identity management providing users with different levels of access to confidential material.

The first phase has put into place direct connections between GSi and other government and inter-government bodies, allowing communications to bypass the public Internet. There are, for example, peering connections between the Criminal Justice exchange, MoD, NHSNet/N3, EU Council of Ministers and TESTA, a network that joins other European Government networks, according to Energis.

Scotland has put a cross-governmental internet called GSx into place, linking the central government, the DVLA, and the TV licensing and Registry Offices.

Seventeen government departments are using a confidential version of the network, called GSi, and civil servants who need to exchange secret data have been allocated their own virtual private networks at different levels of confidentiality. The network is voice-ready, for if and when the government decides to switch over to an IP-based voice system.

The network is already handling one million emails daily, and in June blocked one million viruses and quarantined 2.7 million junk emails, Energis said.

The second phase, coming in September, will add the identity management. Incredibly for a government IT project, this first phase has been rolled out 15 months ahead of the deadline. The entire migration was completed in 18 months.

The ahead-of-time delivery is a contrast to some previous government IT upgrades projects, which have earned a record for being late and over-budget.