This is something you may not know about the Human Rights Act: it hands government the right to kill you in order to preserve its power.

The surprising clause flies in the face of the document's popular right-wing image as a charter for helping villains to undermine the authority of national courts.

Rulings by the European Court of Human Rights (ECHR) on whether judgments break the Human Rights Act (HRA) regularly triggers gnashing of teeth by politicians and rending of clothes by people who worry about issues such as national sovereignty.

Under plans unveiled by home secretary Theresa May, the UK will withdraw altogether from the HRA if the Conservatives win the 2015 general election. Considering how fond the coalition government is of using polls to justify policy, it clearly reckons many British voters would support the move.

Yet could the Human Rights Act really be the friend of those who wish to preserve and protect their national institutions? In a rather disturbing way, the answer is yes: right there in Article 2.

This key part of the HRA document sets out a person's right to life and is the cornerstone of the entire document. But Article 2 contains some little-mentioned exceptions which violently clash with the act's rather tarnished public image.

Clause 2.2.c states that a person loses their right to their life during a riot that threatens the authority of the government.

It reads: "Deprivation of life should not be regarded as inflicted in contravention of this article (right to life) when it results from the use of force which is no more than is absolutely necessary: in action lawfully taken for the purpose of quelling a riot or insurrection."

It is the words "riot" and "insurrection" which jump off the page for dangling over political radicals the threat of extrajudicial capital punishment. It seems the HRA can support a country's government by sanctioning radically inhumane behaviour, not only subvert the rulings of national courts.

Other exceptions to the right to life include shooting prisoners during an escape bid and protecting another person from "unlawful violence". A government can also implement the death penalty during a time of war.

This is surprising stuff which depicts the act in a more muscular way than it is usually shown. Political radicals, people who took part in the England riots of 2011 and supporters of the HRA may pause to reflect that this is one aspect of European law which Britain has not meticulously implemented to the letter.