Are PhD "minimum admission requirements" flexible?
Easiest solution, contact the University's graduate admissions office. Admission criteria will depend on funding source, if you or your supervisor have direct funding for the PhD admissions is usually more flexible, but if you're applying for a competitive scholarship you might struggle to compete against peers with MRes/AU Honours/publications. 

I'm assuming you're going through the UK honours system based on your question. The Aussie system is a bit different where and honours is more akin to an MRes in the UK (see here for more detail: https://en.wikipedia.org/wiki/Honours_degree).