Hi there, the simple answer to your question is that NO a balliff can NOT enter your home without you being there. However there is a loop hole and that is if you say on Monday allow a balliff into your home and agreed that you will pay something and tell him to come back on Wednesday - if you are not in then he can enter without you being there. My advise is this NEVER EVER let a balliff into your home then they have NO rights to gain entry ever. Dont let them try to talk you round either or get abusive this they are not allowed to do report any that do. Just dont let them in ever.
For civil debts, the first time a bailiff comes they can only come in if you let them in, or through an unlocked or open door or window. They cannot force their way in, or push past you if you open the door to them. But - as said by princess - if they have got in because you let them in or they came in through a window - they can return and can then break in, whether you are there or not.
For criminal debts - fines etc. - they can break in the first time they come.