Sorry - solicitor is incommunicado until Monday & this is doing my head in 
Just to give you insight to the kind of guy we're having to deal with - Vendor has practically been booted out by his fellow villagers, he owes money for works done on property he's selling/we want. Throws toys out of the pram if he doesn't get what he wants, has threatened to pull out multiple times as we haven't yet exchanged & he is in a hurry, despite his place being on market for over a year without even reducing the price by 50p! blah blah....
14 suggestions came back from the surveyor. We have asked the vendor to action ONE of these only. Drains need jetting. That's it.
Vendor's agent has told us (finally after 5 calls & multiple emails) that the drains are fine & the agent has removed surface leaves so there really is no issue. (Owner lives overseas)
We asked for works to be carried out by a professional. Obviously this has been ignored.
Lots of too-ing & fro-ing, vendor now says he'll do it after exchange but before completion & will put this in the contract.
I don't trust him AT ALL. What are our options?
*If this is put in the contract and we want a receipt from a pro, can he get out of fulfilling his promise?
To avoid this scenario, can we now go back & say we've reduced our offer by £xxxxx in light of our request being ignored?*
We realise he has no legal obligation to meet us on this but the other factors we could throw into the mix are big. Possibly asbestos. Roof to be re-tiled.
Advice welcome & thankyou in advance.