Correct me if I'm wrong...

Time for a bit of a rant: it's on the subject, still, of buying and selling houses, so sorry if this will bore you but I'm just completely stumped by the whole thing. According to my understanding (and this is where the title comes in) of these matters, gleaned over the past few weeks of frustration and delays, there appears to be absolutely no legally-enforceable deadline by which point you have to have exchanged contracts for buying/selling a house.

In the case of our current move this means that basically any one party in the chain (and there are about 4 or 5 in ours, I think) can slow things down without anyone else involved being able to do anything about it.

In short: we agreed to sell our house to our buyers at the end of January. We had an offer accepted by our vendors at the start of March. We then did all the stuff required of us, in terms of mortgage paperwork and other legal paperwork, before going on holiday at the end of March. We came back mid-April to be faced with loads of stuff to do but expected this so it wasn't too much bother. We duly filled out all the necessary forms and returned them as quickly as possible, chasing up people as and when necessary so as not to delay the whole thing further.

So why, over two months later, are we (those of us actually buying and selling, and ultimately occupying, the houses) sitting here waiting for the exchange to go through?

Why is there no statutory time limit for all this stuff to have been completed? Why can one party legally delay things without any of the rest of us being able to stop them doing it? It's just complete and utter madness.

Our buyers are first-timers, i.e. they've got no property to sell and are buying a nearly-new property, so the legal paperwork took them next to no time, but through no fault of their (or our) own they've had to wait 4 and a half months to move house. We and our vendors have pushed and cajoled our legal representatives and done all the paperwork as quickly as possible but are still sat waiting.

IT'S ENORMOUSLY FRUSTRATING AND STRESSFUL!!!!!!!