Many of the issues Chris Bolt will have considered before Monday morning’s announcement on Metronet’s emergency funding application can be summed up in one question. Why does one PPP contractor – Tube Lines – expect to complete the first quarter of its 30-year contract at around the original budget, while Metronet expects to be at least 25 per cent above its budget?

Andrew Lezala, Metronet’s chief executive, accepts that Tube Lines was initially better managed. He says Metronet, which he joined after its contract started in 2003, should have started its station upgrade programme more quickly. Metronet should also have adopted Tube Lines’ strict control over changes to the scope of upgrade work. Conflict areas on lines managed by Tube Lines are flagged up early and both it and London Underground usually reach clear decisions about addressing them.