It's 170 years since it was last invoked, but Scotland's law against blasphemy still exists – and it's high time it was scrapped, according to a leading Scottish humanist group.

The Humanist Society Scotland are calling on the Scottish Government to repeal the antiquated law, which was last put into practice in 1843, when an Edinburgh bookseller was jailed for 15 months for selling blasphemous literature.

Gordon MacRae, the chief executive of Humanist Society Scotland, said that having a blasphemy law "should be a badge of shame for any progressive nation."

After consultation with the Church Of England, England and Wales threw out blasphemy laws back in 2008 when the Criminal Justice and Immigration Act abolished the common-law offences of blasphemy and blasphemous libel.

Scotland is unlikely to convict anyone for blasphemy again, but repealing would set a good example according to Mr MacRae. He said: "We are calling on the Scottish Government to show moral leadership and to take a stand as citizens of the world by repealing that law and calling for all other nations to put equality, human rights and liberty first."

A spokesperson from the Scottish Government said: "Matters of criminal prosecution are ultimately not for the Scottish Government but for the Lord Advocate as the head of the prosecution service for Scotland, who is required to consider whether prosecution is in the public interest."

The call comes in response to a recently published report on discrimination and persecution against the non-religious by the International Humanist and Ethical Union (IHEU).

Entitled the Freedom of Thought Report, it looked into discrimination and persecution against humanists, atheists, and non-religious people around the world, with in-depth analysis of each country.

Blasphemy is still illegal in at least 59 countries according to the report, and remains punishable by imprisonment or even execution. There are laws against apostasy (the abandonment or renunciation of a religious or political belief) in 22 countries and at least 13 countries still have the death penalty for blasphemy or apostasy. For example, in Afghanistan an Islamic judge may impose a death sentence for blasphemy for men over 18 and women over 16. Those accused are given three days to recant or face death.

Dr Ahmed Shaheed, the United Nations' new special rapporteur on freedom of religion or belief, said in response to the findings: "From Raif Badawi, who was sentenced to 1,000 lashes and 10 years in prison in Saudi Arabia for alleged 'blasphemy'; to Mohamed Cheikh Ould M'kheitir, who is facing the death penalty and incitement to murder in Mauritania for alleged 'apostasy'; to Basuki Tjahaja Purnama, the mayor of Jakarta who is accused of 'blasphemy' amidst an election; to those secular bloggers savagely hacked to death in Bangladesh by vigilante groups; to the scores languishing in prison in Pakistan and Iran and elsewhere for expressing views deemed offensive to religious sentiment; persecution and victimization in the name of religion are both chilling and widespread.

"The IHEU report is an important reminder that the right to freedom from religion or belief is as fundamental as the right to freedom of religion, and that the same human right protects freedom of non-religious thought and non-religious belief as well; and that for some humanists, atheists, free-thinkers and the unconcerned the protection of this right can mean the difference between life and death."

President of the IHEU, Andrew Copson, said the Freedom of Thought Report comes at a crucial juncture in world affairs. He said: "The rights and equality of the non-religious are under threat and there is an upsurge in the suppression of humanist values more broadly. Serious damage is being done to the brand of democracy, to secularism, and there are new threats to all our liberties."