Costain was the largest single supplier to National Highways in 2023/24, just ahead of the Balfour Beatty-linked consortium that carries out M25 upgrade work, Construction News can reveal.It marks the third successive financial year that the contractor and consultant topped the roads body’s league table, and came despite a dip in its roads work in 2023.Costain was paid £450m by the government-owned agency in the year, down from the £522.4m it received in 2022/23.Among its ongoing work is a £285m upgrade of the M6 between junctions 21a and 26, in the North West through Merseyside, Cheshire and Greater Manchester.The second-highest recipient of National Highways cash was Connect Plus, which holds the private finance initiative contract to maintain and upgrade the M25. It was paid £447.9m, just over £2m less than Costain.Its total was £55.3m higher than in the previous financial year, and £100m more than in 2021/22.Balfour Beatty owns 15 per cent of Connect Plus and carries out its work on the road, alongside Egis and AtkinsRéalis.In March, the orbital road was totally closed in both directions, between junction 10 and 11, for the first time ever as work to demolish the Clearmount bridleway bridge and install a large gantry began in earnest.It was the first of five scheduled M25 closures in the Surrey area.Balfour Beatty itself was paid £392.2m by National Highways. Its projects include the ongoing £355m A63 Castle Street upgrade in Hull.The contractor landed the £1.2bn contract to deliver the roads on the north of the River Thames for the Lower Thames Crossing tunnel in January 2023, but a final approval decision on the project has been repeatedly delayed, most recently due to the general election.A decision on the Essex-to-Kent link was put back until October after the poll was announced.Tunnelling work is set to be carried out by a Bouygues Travaux Publics and Murphy joint venture, with Skanska delivering roads in Kent.PositionSupplier name (2023/24)Total amount paid1Costain Ltd£450,072,093.002Connect Plus (M25) Ltd£447,941,226.693Balfour Beatty Civil Engineering Ltd£392,223,595.564Kier Transportation Ltd/Kier Highways Ltd£267,466,664.855Amey OW Ltd£156,709,895.206Skanska Construction UK Ltd£146,728,525.787Ringway Infrastructure Services Ltd£129,710,776.048Colas Ltd£111,636,641.609Jacobs UK Ltd£105,881,382.2810Morgan Sindall Construction & Infrastructure Ltd£103,733,566.2811Tarmac Trading Ltd£102,490,855.8012Galliford Try Infrastructure Ltd£88,103,448.9113John Graham Construction Ltd£87,125,434.3014WSP UK Ltd£79,185,153.7915Bam Morgan Sindall Joint Venture£78,837,555.1516Telent Technology Services Ltd£65,340,819.6417Amey Highways Ltd£64,487,057.2318HW Martin (Traffic Management) Ltd£60,009,797.2319Autolink Concessionaires (A19) Ltd£58,045,229.4320Connect M1-A1 Ltd£52,406,304.54It also emerged in June that a draft of the body’s third road-investment strategy (RIS3) for 2025-30 was postponed due to the general election.Before the election, the Labour Party pledged to defer the “poor value for money” A27 bypass in Arundel, West Sussex, and divert the £320m to fixing one million potholes per year if it gained office.The Linkconnex consortium, comprised of Bam Nuttall, Mace and Aecom, was set to deliver the project.In February, the Office of Rail and Road announced an investigation into National Highways over concerns that its performance had dropped. It said that in July 2023 it identified multiple “potential risks” regarding the body’s capital portfolio and asset-management strategy.Earlier this year, a series of legal cases in which campaigners were challenging its road plans, including the A303 Stonehenge Tunnel and three major new road schemes on the A47 in Norfolk, were won by the government on behalf of National Highways.