I appreciate your response on this.
There was never anything in writing that specifically said we would pay it back when we could afford it.
It was mostly verbal discussions. The conversations mostly went along the lines of "Martin, we want to pay this money back as soon as we are financially able to"... and his response was always "don't worry about the money, it's fine".
This was quite a long time ago, there may also have been emails that said basically the same thing. I'm assuming one of these is the aforementioned promissory note.
But there was never any promissory note signed by either party, of that I am certain. Having looked again at the note provided by his solicitor, it is not even an email, it is a word document, unsigned, dated 12 May 2007, saying we would repay the money with 5 years of the date of the letter, there is also no mention of interest, and I have no recollection of this document.
Our original hope was to pay the money back as soon as possible, regardless of Martins feeling about the money hopefully within 5 years, however that was just before the current finiancial depression, and the house prices dropped quite significantly. They are only now starting to recover, but we can't now re-mortgage because of the CCJ.