Bit more progress this week (albeit slow). Our sellers sellers solicitors have confirmed that they have now received the contract from their sellers and have approved it. Now they have ordered searches (although why they couldn't order them four weeks ago I don't know!). Have also sent enquiries to their sellers.
Praying that these set of searches come back ok.... will be devastated if our chain breaks again 
Still pushing for completion date of 15/22 August. Our mortgage offer expires in Sunday 24th!!