Under the terms of the PPP, Tube Lines was committed to the delivery of substantial improvements to the network via the refurbishment, upgrading and renewing of track, trains, tunnels, signals and stations.

[2] Having followed a similar takeover of Metronet, this meant that all maintenance on the London Underground was thereafter managed in-house and no longer involved any PPPs, although numerous private suppliers and contractors have continued to be used by TfL.

[8][4] The selected model called for the operation of services on the Tube to remain in the hands of the public sector while the infrastructure (including the track, trains, tunnels, signals, and stations) would be leased to private firms for a 30 year period, during which they would enact various improvements.

[8][4] A public denial that the newly-formed railway infrastructure company Railtrack would be involved in the PPP was issued by the government after it was made clear that some parties would refuse to bid if it was.

[11][12] Tube Lines planned to subcontract work to achieve the lowest possible cost, while Metronet (the other PPP consortium) awarding contracts directly to its shareholders.

[13] The bidding process was protracted by political factors, including public disagreements on the topic of PPPs between then-Mayor of London Ken Livingstone and Deputy Prime Minister John Prescott.

[18][19][3] Amongst its first actions was a review of ongoing upgrades, efforts to restructure rolling works packages into longer-term framework agreements, and reduce the number of suppliers involved in pursuit of a 10 per cent reduction in operating costs.

Furthermore, the company committed to the delivery of various improvements across the network, to be achieved via the refurbishment, upgrading and renewing of the track, trains, tunnels, signals and stations.

[4][3] At a cost of £4.4 billion, Tube Lines promised substantial investment during the first 7.5 years of the contract (2003 to 2010):[22][23] In June 2004, the National Audit Office criticised the complexity of the PPP deals, noting they offered "the prospect, but not the certainty" of improvements.

[26] Chief Executive of Tube Lines, Terry Morgan, noted the use of competitive procurement to minimise costs, unlike the closed shop approach of Metronet.

[32][33][34] On 7 May 2010, Transport for London agreed to buy out Bechtel and Amey (Ferrovial), the shareholders of Tube Lines, for £310 million, formally ending the PPP.