If you have rent arrears, then your landlord may try to have you evicted. This is referred to as ‘seeking possession’ and requires a court order. It is against the law to try and get you to leave your home without going to court first.
If you are unable to pay your mortgage, then eventually your lender will repossess and sell your property to realise its value. If you have had your property repossessed then you may find that, once the property has been sold, you may still owe money to your lender or mortgage indemnity insurer.