FranP
1. Are they having trouble getting a mortgage? If they are switching providers a recent survey is often a requirement. A provider may refuse to part with the results to a new provider.
2. Is this a delaying tactic because their buyer has fallen through but they want to keep you while they wait to get another. If so I would put it back on the market if other homes in the area are selling at your price. But perhaps you need to wait now to February. But give them a deadline to exchange
3. What is your estate agent and solicitor playing at? They should be pushing on. Your solicitor is making money out of you for doing nothing.
Re possible mortgage problem? Wouldnt they have got the mortgage all sorted before looking?
It was decades ago now that I bought my starter house - but, as I recall, that was what I did and then went looking. Admitted that - even with the 30% or so deposit I had (by sheer fluke and luck of "right place right time" as I hadnt been paid enough to save it) I knew the mortgage multiplier of that era was 2.5 times your salary and that would have meant a one-bedroom flat. But just in case things went wrong all round - I had decided I was going straight to the starter house (ie a 2-3 bedroom house and in at least a passable area).
That was cue for making sure I'd already got my exact mortgage lender lined-up already - not that hard by the time I'd gone through the tables in a "Which" mortgage magazine of the time looking for the best deal I personally could get. That deal was based on having an employer thought of as very secure and I had duly got it arranged to borrow 3.25 times my salary and taking into account my next payrise if it was soon (and it was). So - yep...all done and dusted and already arranged at around 3.5 times my salary - rather than the standard 2.5 times of that era - and so I'd just managed to "stretch" my way through to getting that "starter house" instead of a flat.
One way or another that buyer is probably "stretching" as much as they possibly can (as most people want - or maybe even need) to get "the best they can" out of their salary - rather than having spare money to play around with and not needing to use all their "borrowing capacity".
So yep...willing to bet they do have a mortgage arranged already. The only way they might not, I would say, is if one of them is playing and hoping to get a better job en route to buying a house and they're dragging it out in case they manage to have the better borrowing power of a better job. I'm unfamiliar with the set-up these days - though I think the last I knew was mortgage lenders took into account the last three months worth of payslips (ie maybe one of them is doing a "3 month waitout" to have that many recent better payslips??). Am guessing you know what their job or career situation is to be able to think how likely (or otherwise) that is...