Long story short, it seems we should be exchanging contracts on selling our house in 2-3 weeks time, but for various reasons we're going to do completion start of October. Previously the seller of our house had agreed to let us stay in thr house and rent off them for fair few months until we get the house we're purchasing in habitable conditions. (i think this was also good for them in recouping some of the purchase price). Since then we've gone for another house and started the searches etc and therefore there's no need to rent off this house from buyers, but it'll take until oct for completion.
Anyway my question is, can the buyer force us to bring completion date forward? And more importantly, if we do need to pay rent, does it come into force from date of exchange or date of completion?