It has set aside a budget of £80m-£130m for the airport tunnels refurbishment project.
The scope of work in the 38 months project includes the installation or replacement of the ventilation equipment, fixed fire suppression, lighting and electrical systems, telephones and CCTV systems.
The main 630m twi bore tunnel was built in 1950’sand is the primary entrance to the central terminal area..
The cargo tunnel built in 1960’s is longer at 830m long and comprises 630m of bored tunnel and 100m of ‘cut and cover’ sections at each end.
Firms have until 23 March to prequalify on the procurement portal