Costs - how much can be claimed from respondent?

I am really unclear on this despite asking my solicitor and reading loads of stuff online. My wife has claimed unreasonable behaviour and intends to recover her costs, she is now refusing to be reasonable in mediation and is threatening to take me to court. If she then runs up thousands of pounds in solicitor's fees in going to court can she claim all of that from me or is there a limit on how much she can claim. I understand that she cannot claim costs relating to financial matters but where is the line between court costs and financial matters if the court is being asked to rule on a financial settlement?

A person who issues a divorce petition can sometimes (not always) claim costs against the other spouse. Those are only the divorce costs - ie the part of the process which ends in decree absolute and dissolves the marriage. Those costs will include the court fee to issue the divorce petition and any legal costs incurred. Unless there is something unusual about the circumstances (such as the divorce actually being defended and fought out in court) these total costs are limited and should not run into thousands.

What can run into the thousands are the costs incurred in resolving the financial issues arising from the marriage if the spouses are not agreed. However, the rule in this separate set of proceedings is that each side pays its own costs. One side will only be ordered to pay the other's costs (or some portion of them) in this type of proceeding if there has ben some type of gross unreasonableness in the conduct of the proceedings.

Many thanks for the reply, that's very helpful.