In addition to the caveats mentioned above, if you have additional professional experience in your field, this may also be taken into account and work in your favour.
It really is subject, uni and department-specific though. Most funded PhDs will specify any minimum requirements, but as gutenberg says, the criteria for being offered a PhD and winning *funding* for a PhD, can be two different things. Also, just meeting the minimum requirements is no guarantee of success if other applicants have exceeded them. If you have 2:1/Distinction or First/Merit, it won't do you any good if the majority of other applicants have First/Distinction.
In my field, funding is rare as hen's teeth so you need the First/Distinction combo to even be long-listed for funding. One of my colleagues had First/Merit (missing a Distinction by 0.2%). They won six PhD places - including Oxford - but had to turn all of them down as they failed to get any funding. It's a harsh world out there.