It's a logistical thing, yes. Its already past the deadlines for applying to many programmes, and even the ones you can still apply to, the funding deadlines are past. I need more time to figure out a research proposal as well. I don't have research background so its going to take some more preparation to get ready to apply!
Do you actually need to write a research proposal?
I know it differs from university to university, but many UK science PhDs already come with the research proposal, project title and funding included (i.e. the professor already has the project ready to go, they just need a PhD student to carry it out) - so often all you have to do is chose which project you want to do and apply... plus a lot of programmes take year-round admissions and some have flexible start dates.
I've applied for 2 UK PhD programmes in the past (in physics and in seismology). In July 2005, I applied for one at Durham University (just after my undergraduate graduation), to start that September - I was offered it in August, fully funded and everything, and had I accepted it, I would have started the PhD a few weeks later. The other, I applied for in July 2009 - it already had the project title and funding included, although after emailing the professor, I discovered that it wasn't due to start until October 2010 (as it was, I didn't get offered it anyway).