What do you understand by marriage? The wedding day itself and all the preparation till then?
If so, how much money are you will to spend?
Is it some kind of contract that is unbreakable and will give you (both?) reassurance that you wont need to look any further from then on?
In which case, even a superficial glance at the headlines here will tell you that it is no such guarantee.
(Number of marriages and divorces, England and Wales
Year Divorces / Marriages
2010 119,589 / 243,808
2011 117,558 / 249,133
2012 118,140 / 262,240
If you both wanted to get married, whatever it meant, you'd be in better shape, but if he starts to resist from now, I'd recommend to either enjoy what you are having now, or move if you want someone who espouses your concept of marriage.
Here are more statistics for you.
<a class="break-all" href="http://webarchive.nationalarchives.gov.uk/20160105160709/www.ons.gov.uk/ons/rel/vsob1/divorces-in-england-and-wales/2011/sty-what-percentage-of-marriages-end-in-divorce.html" rel="nofollow" target="_blank">webarchive.nationalarchives.gov.uk/20160105160709/www.ons.gov.uk/ons/rel/vsob1/divorces-in-england-and-wales/2011/sty-what-percentage-of-marriages-end-in-divorce.html