We have not signed the contract to sell the house and can't do so because of financial matters do I have to pay any of the cost that the was buyer has paid out ?

If you haven't signed the contract, what money has the buyer paid out? Typically the buyer will start incurring expenses for things like home inspection, title search, etc only AFTER the contract is signed. Prior to you signing a contract to sell there is no obligation on your part to actually sell the property.

He has paid for survey and solicitors do I have to cover that cost ?

You sound not in the US...
In the US, buyers will typically spend money between the 'offer' acceptance and the 'purchase and sale' agreement.
The offer is designed for the buyer to have various reasons to back out, such as inspection report and ability to get a mortgage. It isn't a way for the seller to back out.

If this goes to a lawsuit, I suspect that you will have to pay for the survey at least, since that is considered an expected expense. Not sure about solicitors charges. It's reasonable to pay one at offer time so that they can advise on the next step, but some people wait until the P&S needs to be examined.

he has paid for survey and solicitors do i have to cover that cost ?


His solicitors allowed him to get a survey without a written contract in hand? No, you are not liable for those costs, but it seems that the solicitors might be.