When people bash the DfT for organising the IEP scheme rather than letting the individual TOCs manage it, remember what was so good about the trains they're replacing. If we let the ICEC and GW franchises manage the procurement on their replacements for the 125s then it's very likely that each company could end up with a unique fleet of trains. Unique fleets are not at all a good thing unless there is a very good reason (i.e. the Pendolinos) since then you are not able to do send them around the country without expensive depot works and staff training. If there are ever any 125s lying unused by one operator then any of the others can easily pick them up with a minimal amount of effort as they already have everything they need to run them.
If we let the 125s be replaced piecemeal by lots of different designs, this will become much more difficult and for what benefit? Apart from possibly replacing the 225s with more Pendolinos, the orders for the diesel/bi-mode replacements were always going to need to be a new design unlike anything else on the network (which is the reason letting TOCs order more Turbostars or Desiros isn't as bad a thing). The procurement of trains of such national importance is always going to need quite a bit of government oversight and control - despite what Richard Branson says his company were forced to get the trains they did by the Government.
I'll bash the DfT all I like. It was their obstinate opposition to an electrification programme that first led to the initial IEP concept, as a diesel-powered HST replacement, when just about any sane and rational organisation would have seen the need to replace a life-expired diesel fleet as the ideal opportunity to electrify.
When that finally changed, the IEP began to evolve, but with yet more false starts, such as trains with one electric and one diesel power car, until we finally got to what will actually be built.
This farce has been going on since 2005. It will have taken 10 years by the time the first prototype turns a wheel and 12 to passenger service. FGW's HSTs are having to undergo yet another life-extension overhaul to keep them going for four more years.
If DfT had embarked on an electrification programme in 2005, which could likely have covered a lot more of the system by now (such as Worcester/Cheltenham/Weston in the GW area and Hull/Middlesbrough on the East Coast) and left it to the TOCs to sort out the trains, we would have been running around in new electric trains some years ago, most likely some sort of Pendolino derivative, whether tilting or not, and bi-modes might never have happened, or been far less numerous.