The Student Union was left wing when I was there - at the time the dominant force was "The Broad Left" lead by a mature student who I guess was on a Trade Union Sponsorship. He spent his time conflating the concept of a Trade Union and a Student Union trying to gain funds to support "Our fellow Union brothers, the miners" as "we had so much in common". I suspect Arthur Scargill and the NUM didn't give a flying fig about the issues facing students at the time.
What usually happened is that some lunch time meeting would pass some resolution to the joy of the BL - until the engineers and medics got wind of it. At that time they constituted over half the University numbers.
A call would go out in the Engineering students newsletter (whose name I forget) and the rather more prosaically name medics newsletter (Rectum - "The mouthpiece of Leeds Medical and Dental Students) to overturn it. Which we usually did - to howls of "it isn't fair" from the BL.
Happy days!