Metronet: the £17bn Tube PPP whose £2bn overrun pushed it into administration

Metronet was one of two private infrastructure companies created by London Underground's 2003 Public-Private Partnership, the government's answer to decades of underfunding. Five blue-chip firms — Atkins, Balfour Beatty, Bombardier, EDF Energy and Thames Water — each held a fifth of the equity, with a 30-year, £17bn mandate to maintain and upgrade nine of the twelve Tube lines, including the busy Bakerloo, Central and Victoria lines.

The overruns came fast. By 2007 Metronet was carrying an estimated £2bn overspend, having upgraded less, more slowly, than its contract assumed. It insisted the money was owed for events outside its control and took the row to the PPP Arbiter, claiming around £550m. In July 2007 the arbiter awarded only an interim £121m; the shareholders refused to put in more equity, and on 18 July Metronet called in Ernst & Young as railway administrators — the first big casualty of the PPP experiment.

Every subsequent review pointed the same way. The House of Commons Transport Committee said the PPP had rendered Metronet's contract 'pretty much useless'; the government and the arbiter held Metronet and its shareholders primarily responsible; and the National Audit Office in 2009 put the cost to the taxpayer at up to £410m, finding the key cause was Metronet's own poor risk management and governance of its contracts.

Transport for London took the company out of administration in May 2008 and kept the upgrade work in-house. The contrast with Tube Lines — the other PPP contractor, which had no substantial cost overruns on the remaining three lines — showed the failure was not the model but the firm that promised more than it could govern.

£2bn overspend; shareholders lost hundreds of millions of pounds; NAO put the taxpayer cost at up to £410m

Governance was split five ways among shareholders with different priorities, so no one owned programme delivery or its risks end to end.

The consortium underestimated the condition of a Victorian network, pricing renewal work on optimistic assumptions rather than surveyed reality.

Poor contract and risk management meant incentives meant to reward early delivery were consumed plugging day-to-day overspends.

Dispute-first culture: rather than renegotiate, Metronet bet the company on an arbitration claim the arbiter largely rejected.

When the claim failed, shareholders declined recapitalisation, so a working-capital gap became insolvency within days.

Winning a giant infrastructure contract is not the same as running it. Without single-point accountability, consortia price risk optimistically — then argue blame instead of managing it.

TfL completed its takeover of Metronet on 27 May 2008 and forecast £1.4bn of spending on the ex-Metronet lines for the coming year, bringing renewals back under public control. The NAO's 2009 report criticised the Department for Transport for sitting out the slide into failure, and the PPP was quietly wound up — Tube Lines was bought out by TfL in 2010. The shareholders wrote off their entire investment, and 'Metronet' became the standard citation for why performance-risk PPPs need deep operational governance, not just balance sheets.