Your solicitor can phone and find out. Or ask the estate agent to ring the seller and find out, simple as that. Just don't count your chickens is all if the seller's are delaying. It's unusual that they would not sign ASAP in this market. I was in this situation and my solicitor said once she had released the signed contract and issued the 10% cheque we could not back out until the closing date had passed. It transpired then the sellers were fighting amongst themselves and they pulled out of the deal.