How to accept a Master's at one place and keep the other as a conditional>

Hi,

I've applied for a Masters course at the University of Birmingham directly and at Oxford Brookes via UKPASS. Brookes have already made me an easy offer through UKPASS, but I'm still waiting on Birmingham.

How would I accept an offer at Birmingham, whilst keeping my Brookes offer open in case I don't meet the entry requirement? The Birmingham application was direct via they're website, so I can't make a conditional and insurance offer like you can with UCAS Undergraduate applications.

Thanks in advance!