How can my disabled son get cover for joint mortgage payments?

He is on universal credit and I’m worried that if his girlfriend is unable to work he will be liable Q My son and his girlfriend are buying a house together. He is disabled and on universal credit and as a result, has very little income. So with our help, he is putting down half the purchase price while his girlfriend is contributing 10% in cash and will be paying the whole of the mortgage on the rest. Because they will jointly own the property, the mortgage lender is insisting on having b