Fantastic temporary. 
We're starting to get really annoyed. I made DH phone the solicitor (he usually emails, so he gets bland responses) and they're still waiting for responses to really simple routine queries. It's been 4 weeks of waiting for a response.
The vendors don't appear to know where the deeds to their house are and have contacted the solicitors they used when they bought the house to try to get a copy. It's just nonsense. They need to just order a copy from the bloody land registry.
We are also waiting for the estate management company to respond to the standard questionnaire, and something about needing a copy of the original planning permission for the development. I am very annoyed that no one has been harassing the management company for a response (and I'm slightly skeptical that the vendors' solicitor haven't received the response yet, but aren't passing it on). And they can just get a copy of the planning permission from the council.
The third one is also weird. The development isn't entirely finished yet, so the council haven't adopted the roads yet. Our solicitors asked them to buy an indemnity for this but their solicitors claimed they couldn't find one.
Our solicitors have had no problem getting a quote for one and have asked the vendors to pay.
So, we suspect the vendors are stalling (we have no idea why). None of this should take a bloody month to resolve. DH has texted the vendor and told him that are buyers are very unhappy and want to agree a completion date and exchange contracts ASAP.
It's annoying because we have done everything to make the process smooth, including organising a mortgage that would be very quick (because the vendors said they want a quick sale) rather than the cheapest possible deal.