The launch of the third and final military communications satellite of the £3.6bn Skynet 5 programme has been delayed by software problems.

Technicians delayed the launch after software testing did not go to plan.

The system aims to provide secure military communications for the Ministry of Defence.

The first two satellites entered space in April and November last year.

They will provide a high-bandwidth secure communcation network for voice, data and video traffic.

Scientists now hope the satellite will lift-off from Kourou, French Guiana, later this week on an Ariane 5 launch vehicle.

The system has been supplied Paradigm, a division of EADS Astrium.