McKay started this week as procurement director for construction on the HS2 project, reporting to commercial director Beth West.
He will play a key role on the project overseeing the award of vast civil engineering contracts on the high speed railway route.
McKay was head of procurement and the supply chain for four years at Lend Lease before taking up a project manager role on the Elephant & Castle redevelopment for the firm.
The HS2 procurement team is gearing up to start prequalifying firms for tunnelling and surface line frameworks in the first half of this year .
Phase one of the project will be carved up into nine vast tunnel and surface contract packages, to be let as early contractor involvement deals worth between £500m-£1bn.
Around 25% of the the 230km route will be in tunnels with another third running in cuttings.