I might be having a blonde moment but i didnt complete any change of name papers when i got married??? should i have?
Sorry didn't mean to confuse you. If you have an Australian marriage certificate that is usually sufficient to change your name on your drivers licence, medicare, etc. In some cases, such as getting married overseas, you may be required to get a change of name certificate issued instead.

Where are you going? If you are using your Aus passport you should be fine, but if you are using both I would either get the UK passport updated or take marriage certificate OR change of name certificate with you