In English Law a valuation of a house is subjective unless there is a professional valuation by an independent valuer (not an estate agent - that is always going to be very subjective - surveyors reports are seen as objective and are used during the house purchase process to prevent a potential buyer being overcharged by either an estate agents optimistic valuation or a sellers over optimistic and maybe somewhat fraudulent account of any property defects that are apparent to the seller).
Also to be binding a valuation has to be within six months of a financial settlement and when the house value is in dispute then an independent valuer needs to be instructed, usually both parties paying half the costs of the valuation so that their is no prejudice of costs.
What your husband is doing is concealing and ommitting salient and relevent facts.
Imagine a without prejudice offer written another way,
Dear I hate you stbx wife
I have a fantastic home abroad which I regularly visit, get an income from and is worth £300,000. It is fantastic.
However, I am not prepared to disclose this property on my financial e, I am not prepared to allow it to be considered during the split of finances in our divorce in financial remedy.
Also, although the mortgage on the FMH is a joint one I am only prepared to pay £50 a month to that, I have no intention going anyway to repay the capital, I couldn''t give a toss either about you or the shareholders of the bank whose money we have borrowed.
You can have the house, I want my name taken off at the land registry and in a couple of years time I am not paying you any maintenence (the £50 is for you personally and the mortgage - sort that out how you want to).
BTW I think you are an old cow. Please note that as I have marked this letter without prejudice you have not got a hope in hell of producing this in court, including the addresss of the property which you will note is the correspondence address as I am writing you this lovely love letter whilst sitting abroad and sipping my gin and tonic with my considerably younger and definitely more sexy woman than you ever were.
I believe in family courts you can produce a without prejudice offer if it is definitely prejudiced, you can not rely on proceedure if you are abusing process.
He has not disclosed the property on his financial e, he has made a very unreasonable offer regarding the house and finance - leaving you a few years of poverty before you decide what to do about the house, he has not disclosed the property abroad or made any allowance for that in the prejudiced - IT IS NOT without prejudice as to be without prejudice it has to be fair and based on something realistic.
Negotations in all courts are supposed to be honest and you are supposed to negotiate openly to get a resolution.
If you look at the rules for a claim of professional negligence you will see that your negotiations before it gets to court have to be open and you must consider offers.
If you are not brave enough to disclose that offer immediately I would take it to a hearing point out what you say and then ask the judge if he/she would like to see it.
Also do you know the address of the property abroad and what it actually is?
If you read my post again a family judge did accept a without prejudice offer - actually it was my offer which had not been given to me by my legal representative which I had wanted to be an open offer.
The other side disclosed it in a court bundle to a family High court Judge. I disclosed to the Judge but not the other side (only because at a previous hearing I had been accused of abusing process by including in a bundle correspondence between me and my solicitor). The judge questioned the other side as to why they had disclosed it, he questioned me on why I had not disclosed the documents between me and my solicitor and I explained.
I actually wanted the without prejudice offer to be disclosed - I would have done it myself if my solicitor had done their job and sent me a copy.
Also what the family High Court Judge told my ex-s solicitors is that they should have protected their clients position with a without prejudice offer (as we were in appeal court) if they really believed their client had right on his side.
Without prejudice offers to settle are supposed to be more generous than you really believe realistic and that is why in general without prejudice offers cannot be disclosed. The without prejudice offer is supposed to be generous as it stops proceedings - there are no real winners as we all know especially when dealling with a bitter, vengeful and money grabbing stbx or ex.
There are three main hearings when deciding who should get what, the first two are without prejudice so that`s FDA and FDR, offers are considered, in fact required.
The last hearing rather surprisingly called a final hearing is not without prejudice and only open offers can be considered, nothing said at FDR can be mentioned at FH, by that i mean what the judge had to say or any offers headed without prejudice.