Construction of the permanent Midland and Airport lines will be staged from September 2020 until mid-2021. The works will be done in stages to limit impacts to residents and train passengers as much as possible. Given the proximity to the operating Midland Line some out of hours works are required in September and October.

Progress in the Airport Line's twin-bored tunnels has really gained momentum, with 90 per cent of the tunnel invert slab now poured and cured. More than 4300 sleepers and about 17km of welded rail strings have been placed, with around 3km of skeleton track (rail strings clipped onto the sleepers) assembled.