The harsh truth is that Boris Johnson has very little room to manoeuvre over his transport budget.
He is likely to be forced to raise fares even if that allows his political opponents to make capital out of the increases.
Virtually everything that has happened since he became Mayor has reduced the amount of money coming into Transport for London’s s coffers.
Most importantly, there is a four per cent reduction in the number of Tube passengers, caused by the downturn.
Then there is the collapse of Metronet, the infrastructure company, which, at least in the short-term, has blown a hole in his budget.
The Tube’s Public Private Partnership is in a mess, with the other infrastructure company, Tube Lines, also demanding more cash when the system is reassessed next year.
And work has started on Crossrail, the £16billion scheme which will absorb yet more cash. Nor has Boris helped his own cause.
He has embarked on an expensive and unnecessary programme of replacing bendy buses with conventional vehicles.
He is scrapping the Western extension of the congestion charge, which will not only be expensive to dismantle, but reduce the amount of money coming in from the scheme, one of the few ways he can raise cash other than by fares increases or extra taxes.
The latter is politically unpalatable for someone elected on a low-taxation platform.
Boris is finding out just how difficult it is to run transport in a huge city like London. The demands for investment are insatiable and there is a very good case for them. The trouble is someone has to pay – and it usually ends up being the farepayers.