Any contract tainted with fraud is unenforcable in English Law. Further, I would refer you to a House of Lords ruling on 26/10/99 in Barclays Bank v Boulter (Mrs), regarding undue influence.(posted 8601 days ago)I cannot imagine a Court would enforce the deed. Were you misled as to what you were signing and were you doing this under some duress from your ex - it may well be in your favour if the answer tunrns out to be 'yes'! If this was not in your financial interests to sign such a document this would also be in your favour. Tha'ts of course if you did sign it. Is there any possibility you do not remember siging the deed ? Is the signature really yours, or a copy of your signature ?
Best wishes Vic