I did my undergraduate degree passing with 2:2, a couple of years later i did an MSc, which i gained a pass. I worked in the industry for 4 years. It has been 12yrs since passing my MSc and ive returned to working in the srea of my studies which has re-ignited my passion and dream of doing a PhD. But most places want 2:1 and merit, plus I've been out of academia for so long i feel tge jump too big. So, can i do an MRes? I know it is a madters degree and i already have a masters.

Your industry experience will matter more than your MSc from 12 years ago. Universities consider mature students differently and understand that your experience is valuable. Though have you considered funding for a second masters? Also, you will probably get asked about your pass at MSc and it would be good to have a answer explaining that.

You most certainly can. At least 1//3rd of my cohort did MSc and then did the MRes before the PhD.

Meardonna, I think an M.Res would be great for you. Alternatively, there are some Doctoral PhD programmes which offer the 1st year of the degree as a taught component, in which students are exposed to different areas of research, reading groups etc.. before choosing their specific topic. I knew fellow PhD students in the Cyber-security area who undertook such a doctoral training programme. I myself did the classic MPhil/PhD with upgrade to PhD-proper in the 2nd year - this didn't have such a year, but I already had a defined problem to work on. Good luck!

I emailed the university i want to study at to ask about MREs. Saying i was a mature student and had Bsc (hons) 2:2 and an MSc pass, but they said they wouldn't accept me for MRes either even though have a masters! They listed some MSc courses they said would suit me better! Feels like my MSc is useless! Going to a postgraduate toadshow so hopefully talking to someone face to face maybe better?

Hi. As I personally have MRes, I do not think it is the best choice. The MRes is a non standard degree especially outside the UK. Also it takes theoretically one year but could take longer.
Now let us look for what we can do. You could email potential supervisors with a cover letter. You do not have to mention your grades in the cover letter. Just write them in CV. You might a positive feedback from a supervisor. In the mean time, you could apply in several universities for either MRes or another taught Master but in a slightly different field.
By the way, how do you plan to find the Master? do you think you can afford one year without a salary?

I'm currently not working at present following a bout of severe illness, and multiple surveries. so am slowly getting myself back to full strength, I'm using the time to get my career back on track as had done a bit of a detour.. Im currently in an unpaid internship 2 days a week. I am expecting some money next year which i intend to use for paying for my degree. I have a masters in environmental management, I'd got a scholarship for it, but my heart lies in ecology, conservstion and animal behaviour i want to do my PhD on behaviours caused by anthroprogenic influences, mainly considering either rays in captivity, or rescued seals rhen looking at how adjust back in the wild. I've seen an MRes in animal behaviour which looks great and could help me get on track. Im currently sending my CV and a covering letter to a few different potential supervisors asking if they have any voluntary research opportunities to help me get some more experience and get back on track.

You are doing fine by sending CV to different supervisors. Moreover you can add that you would like to have a short face to face conversation if they are in the same or a close by city. Do not be disappointed because some will never reply or reply negatively. Just keep your motivation and your day will come for sure. All the best.