Original sentence: Games between these two biggest clubs in Scotland (and among the biggest in the United Kingdom) are characterised by sectarian posturing on the part of a minority of both Rangers and Celtic supporters, which can and often does spill over into violence.In short, this is a highly political contest, where religion is a backdrop.Old Firm ties (matches) have been known to be a flashpoint for political strife in Northern Ireland, as many Celtic supporters still tend to support Republican movements in the north of Ireland, fighting for a United Ireland, whereas certain Rangers supporters are more in favour of retaining control of the north of Ireland as part of the UK, and therefore support groups such as the LVF and the UDA
Edited sentence: Games between these two biggest clubs in Scotland (and among the biggest in the United Kingdom) are characterised by sectarian posturing from Celtic supporters, who to this day continue their age-old tradition of violence against protestants.Old Firm ties (matches) have been known to be a flashpoint for political strife in Northern Ireland, as Celtic supporters support Republican movements such as the IRA, led by British politicans Gerry Adams and Martin McGuiness