The National Secular Society has written to Channel 4 News to express concern over the programme's censorship of the Jesus & Mo web comic, which was shown as part of an item on the ongoing row over the Liberal Democrat candidate Maajid Nawaz's use of the image on Twitter.

In a letter to the programme's editor Ben de Pear, the NSS warn that the decision to redact the "Mo" character from the image sends the wrong message about free expression in Britain, and stereotypes Muslims as being inherently prone to extreme reactions over such images:

By redacting the picture of 'Mo', you have contributed to a climate of censorship brought on by the unreasonable and reactionary views of some religious extremists. Rather than defending free expression, one of the most precious pillars of our liberal democratic society, you have chosen instead to listen to extremists and patronise British Muslims by assuming they will take offence at an irreverent and satirical cartoon. By taking the decision you did, not only did you betray the fundamental journalistic principle of free speech, but you have become complicit in a trend that seeks to insidiously stereotype all Muslim people as reacting in one uniform way (generally presented as overly sensitive and potentially violent).

The letter points out that Channel 4 risks creating a precedent on the use of such cartoons in the British media, and stresses the importance of UK broadcasters upholding free expression when blasphemy is still punishable by death in many countries:

In a world where the notion of offence to those with religious views is being used to control and punish people of all religions and none, the UK has an urgent responsibility to uphold freedom of expression in the face of religious extremism. Its news outlets share in this responsibility.

(Update: Channel 4 has issued a statement responding to accusations of censorship: "The senior editorial team decided that the showing of the entire illustration, whilst likely to cause offence, was not integral to the story, and therefore took the decision to pixelate. Whilst we acknowledge your views, we believe that on balance this was the correct decision and as a rule, where we consider the likelihood of significant offence to our audience, we will attempt to mitigate against that. As to not pixelating the image of Jesus, it was not felt that the same level of offence was likely to be provoked as the image is commonly depicted in cartoon form.")

Away from Channel 4, the Jesus & Mo row has also led to controversy at the University of Plymouth, where members of the Islamic Society attempted to have an event cancelled because the speaker would not condemn Maajid Nawaz. Sheikh Dr Usama Hasan, a senior researcher at the counter-extremism think tank Qulliam, of which Nawaz is executive director, spoke at the university last night, but faced a small protest and an earlier appeal to the vice chancellor Wendy Purcell to withdraw the invitation to Hasan. In a letter to Purcell the Islamic Society said:

The decision to invite a member of the Quilliam Foundation by our chaplain David Evans has been extremely misjudged and we fear that if this invite is not withdrawn, a long term feeling of mistrust and suspicion will arise between the Muslim student community and the chaplaincy – the very chaplaincy set up to create a safe environment for the faithful and inter-faith cohesion.

I would request that you consider the withdrawal of the invitation of Usama Hasan of the Quilliam Foundation and cancel the event. This would be a clear statement that the university listens to the concerns of its students and cares about the peaceful and cohesive environment we enjoy on campus.

Amid the ongoing row, Nawaz himself has spoken out, using a column in the Guardian to explain that his aim in tweeting the cartoon was to defend Islam "from those who have hijacked it just because they shout the loudest":

My intention was to demonstrate that Muslims are able to see things we don't like, yet remain calm and pluralist, and to demonstrate that there are Muslims who care more about the thousands of deaths in Iraq, Pakistan and Syria than we do about what a student is wearing. My intention was to highlight that Muslims can engage in politics without insisting that our own religious values must trump all others' concerns, and to stand before the mob so that other liberal Muslim voices that are seldom heard, women's and men's, could come to the fore. And many such Muslim voices have been heard this last week.

While the petition to have him deselected as the Liberal Democrats' candidate for Hampstead and Kilburn has attracted over 21,000 signatures, Nawaz appears to have retained the support of the party hierarchy. Speaking to London's LBC radio this morning, the party's leader NIck Clegg said that Nawaz will not be dropped as a candidate. Clegg expressed support for free expression, but explained that he would not personally have tweeted the image:

He is not going to be dropped as a Liberal Democrat candidate. He has the right - as any Muslim, non-Muslim or anyone of any faith or none in this country has - to say things even if that causes offence to other people.

It so happens that what he did does cause real offence to many, many Muslims in this country. All I would say is that we have to make sure that that debate, sensitive though it is, is conducted in a respectful way in moderate terms.

I would not have tweeted that thing, clearly. I will defend anyone's right to deploy the freedom of expression in this country. I'm not going to start censoring people in a free society.

Finally, if you're interested in hearing the Jesus & Mo cartoonist's own take on the story, you can watch his Newsnight interview with Jeremy Paxman here: