Earlier this year, the UK government set out a proposal to make it easier on UK residents to keep signal while venturing into more rural areas by setting up 'national roaming'. Essentially, the idea was that someone on Three that loses signal could then roam on o2's network which has coverage in the current area, similar to how UK residents roam internationally while abroad on networks like Movistar. Earlier in the year, when the proposal was put forward, it was put down by the networks saying that it would remove their motivation to further improve their networks in rural areas. Now, the major networks have said that the scheme would be unworkable and that the timetable put forward by the government is unrealistic.
According to the Financial Times, networks have said that it isn't as easy to cut up networks like the UK government is expecting. As well, the networks have said that the timeframe to get things started by early 2015 is unrealistic however, they have said that they're more than willing to work with the government to reduce the number of "not-spots" with no coverage at all. While national roaming doesn't sound like an overly good idea, there is word that the UK government could force the networks to share their networks to make overall coverage of rural networks better.
There is a little hope though, as Three have come out and said that they're happy to improve rural networks saying that "we support the principle of expanding coverage to address areas less well served and are in discussions with government about the most effective means to deliver that". I've recently just switched from O2 to Three and I now have 4G where before I didn't even have 3G coverage, and while I'm not exactly in a rural area I'm hardly in the center of London, either. It's clear that other networks are doing more than others, with Vodafone falling behind on even their national 3G target set by OFCOM, but at this point any sort of progress on getting rural England more connected is a good thing.