The mortgage company will almost certainly have a clause in the mortgage that says you pay for all the costs if this goes tits up in these sorts of circumstances.
Which is nearly impossible for most things. How many of you have a receipt for the TV, car, bicycle etc. to hand? I think in some situations the bailiff is supposed to list what they are intending to take and the debtor can dispute it, but all bailiffs will have lots of experience of debtors going "not mine" to avoid goods being lifted.
Also, can not take tools of trade, equipment and cars under £1350 worth total if you need it for work or study. Other restrictions apply too e.g. motability, blue badge.
There is an agreed format of income and expenditure statement that most lenders, creditor types, etc. are signed up to, if I remember correctly. If you sit down and fill one out with the help of a charity a lot of people will accept the figures and agree repayments on that basis.
Also see StepChange Debt Charity Debt Remedy Tool https://www.stepchange.org/start.aspx