Ernest Bevin both in his actions for the people of Bristol and for all who reside nationally in Britain would be a wonderfull choice to be commemorated on the plinth.
Bevin was born in 1881 and as part of a farm Labouring family left school at the age of eleven with very little in the way of education. He went to work on Bristols Docks as a labourer where by the time of his early teens he was active in forming the Bristol Carters and Loaders association which did much to promote the raising of working conditions for those labouring on the docks.
Bevin then went on to co-found the powerful Transport and General Workers' Union. and served as it's General Secretary in the years 1922–1940.
It was then that Winston Churchill asked Bevin to join the wartime coalition government as its minister for Labour. In that role, Bevin brought into being the Land Army. which did so much to keep Britain fed throughout the conflict. He also was responsible for transforming almost all of Britain's manufacturing industry to armaments and other essential production that was so needed during those terrible year's.
In 1945 Bevin became Foreign Secretary in the Clement Atlee Labour Government that brought into being the National Health Service and Welfare state that the United Kingdom still so benefits from even today.
Despite being poles apart on the political spectrum Churchill and Bevin became firm allies during those war years both knowing and agreeing on exactly what was required to maintain the United Kindom in being, and through that, leading the world in opposition to tyranny.
On the death of Ernest Bevin in 1951 Winston Churchill spoke in tribute to him, stating, "Bevin had many of the strongest characteristics of the English race. his common sense, his rough simplicity, sturdiness and kind heart, easy geniality and generosity, all are qualities which we who live in this famous island regard with great admiration".
Indeed it can be stated that Ernest Bevin is a person that has stood very large in Bristol's past, and in a Britain that many have wished to migrate too in past years and even until today still wish to live within.
Wikipedia link to Ernest Bevin can be found here:-
en.m.wikipedia.org/wiki/Ernest_Bevin