Thanks for your question.
The practical reality is that the lender will not advance you the mortgage funds unless the letter of consent has been executed by you. All non-owning persons in mortgaged properties should sign one, it is in the mortgage conditions that the owner of the property signs up to.
Essentially it re-enforces the primacy of the lender's charge. It means that they have first call on the property. It means that you would not be able to claim any interest in the property before their rights under the charge are secure and enforced.
The equity in the property would still be a matrimonial asset which would be included in the asset pool to reach settlement over. The fact that you sign the letter of consent just means that you acknowledge there is a mortgage and that this would have to be paid first in the result that it is sold.
If your wife dies before the mortgage is paid then it obviously depends on what she has directed in her Will, but the mortgage repayments must continue to be met (ie. by her estate and executors) until such time as it is taken over or the property is sold depending on her Will.
I would suggest investigating her taking out an life insurance policy in the sum of the mortgage so that monies would be available to repay the mortgage upon her death.
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