I have just learned my Husband falsified our mortgage a decade ago, what next?

He bought a house 10 years ago, I already owned a flat and we were not married so my Husband bought it in his name only. We had only been dating 6 months.

He paid £500k, £450k was mortgaged over 25 years. He put that he earned £95k when in reality he earned about £35k. He had a lodger and comfortably paid the mortgage using his income and lodger income. Then I moved in as well and he began to even overpay the mortgage with 3 of us in a 4 bed house.

Fast forward 5 years and my flat is rented out (it makes £700 a month after tax) the lodger has gone and we are married and he renewed the mortgage for another 5 years with the same company. He says they did not ask for his earnings.

This brings us to the present day, we need a renewal on the mortgage in 2 months. My husband insists we can not change provider (this is how I found out about him lying about wage) or any of the terms of the mortgage as we will need to go through affordability and he still only earns £50k and would not qualify for the mortgage still, even though the balance is only £250k now and the property is worth around £1m (he did extensive renovations and extended it years ago).

What on earth do we do now? We have about £750k equity in this place and can afford the new mortgage but it was obtained deceptively. My husband point blank refuses to come clean and would rather sell the house and downgrade. I work in law, so it’s very uncomfortable for me to be attached to this. Is there a chance this is found out or has he got away with it?