You could say SISO is a name for the system by which MEPs claim back expenses. They are entitled to €300 per day for food and accommodation during their workdays at the European Parliament. It turns out that in practice, many MEPs turn up, claim their expenses and leave without doing any work, and so the moniker stands for “Sign In, Sod Off”. Here is a Youtube video of two MEPs reacting angrily to getting challenged about their expenses after they pocketed their €300:
This brazen attitude only reflects the corrupt atmosphere of Brussels politics. It encourages a pro-EU outlook as the MEPs begin to value the remuneration involved with working at Brussels, over and above the desires of the populations they represent. This does not apply to all MEPs of course, many of whom fight on a genuinely Eurosceptic platform. yet, this highlights why Brussels seems so deaf to the justified rage directed at them and the thoughtless policies they want ram down everyone’s throats.
SISO exemplifies much of what is wrong with the EU: the frivolous and unrestrained spending, the naked self-interest to the detriment of Europe and the Great British Public. They live in a bubble, remote from the concerns of the average man or woman, churning out regulations that nobody wants. Britain “signed in” to this circus, so the quicker we can “sod off” out of there, the better.