10 years ago the Department for Transport produced a report which claimed that there would be no need for any more electrification, as trains of the future would be powered by magic beans (or "bionic duckweed" if you're Roger Ford). This was widely derided and an electrification programme of sorts was started. Subsequently, nearly every one of those projects which have completed was late; some have been abandoned (and some of those should never have been considered) and a few have gone wildly over budget.
All of a sudden, magic beans seem like a more attractive proposition when it comes to powering the railway, particularly to a politician who has no inclination to appear before the Select Committee explaining why another project has not completed on time. Neither does the Secretary of State fancy getting an earful from members in the Commons Tea Room complaining on behalf of their constituents and their continual weekend bus replacements.
What's needed is a more sensible investment routine which doesn't promise the earth in five-yearly instalments. So far as electrification is concerned, I'd be saying "we've got this much resource; what can we do with it every year?"; in other words can we commit to, say, electrifying 200 track-kilometres per year and, given that, what schemes give the best return?