This weekend, members of the University and College Union will meet for our annual congress. We had invited leading Colombian academic Miguel Angel Beltran Villegas to join us in Manchester to make a keynote speech. He won't be joining us though. He will be standing trial in Colombia for the Orwellian-sounding offence of "rebellion".
His "offence" was to publish academic papers and articles on the armed conflict in Colombia, to criticise the government's education policy and to highlight abuses of human rights. He was arrested and imprisoned a year ago and is only now being charged. And there are hundreds of others who have been imprisoned without trial for rebellion.
Dr Beltran had also been active in the campaign for better working conditions for academics and for an end to the rampant privatisation of the higher education sector in Colombia - issues that will be close to the heart of many UCU members. The defence of academic freedom will be a key issue for UCU members in Manchester, but they will not fear for their lives making that defence. A recent study published by the UCU, the National Union of Students and the Justice for Colombia campaign found that Colombia was the most dangerous place in the world for student leaders and the most dangerous place on Earth to be a trade unionist.
In the past 20 years, 4,000 trade unionists have been killed. Add to this the estimated 30,000 forcibly disappeared people, the 4 million internally displaced and the regular assassinations of journalists (seven last year alone), and one begins to understand why the work of those such as Dr Beltran is so important.
The abuses that he highlighted included assassinations of several university professors and trade union activists, and widespread and systematic murders, since verified by the United Nations high commissioner for human rights, of civilians at the hands of the Colombian army.
Last year, I visited Colombia. In Bogota women's prison I met another academic, Liliany Obando, who had been jailed for her political views. She, like Dr Beltran, taught and published material that, according to the authorities, was subversive. And she too had not been convicted of any crime and remained in appalling conditions, harassed by the authorities and accused of a whole manner of crimes for which no evidence had been provided.
While I was in Colombia I heard countless stories of the army torturing and killing civilians, the secret police targeting trade unionists and members of the political opposition, and academic freedom and other basic civil liberties being violated with absolute impunity.
I also met with Colombian officials who assured me that none of this was true and saw first-hand their efforts to mislead international opinion and convince outsiders that the situation had improved. Yet none of their claims stood up to even my basic scrutiny.
The facts are that people continue to be murdered, disappeared, exiled or imprisoned for criticising the Colombian regime. Forty years of civil war have come at a huge price for Colombia and its people and they deserve much better.
But there is hope. During my trip we visited another prisoner, Martin Sandoval, from Colombia's largest human rights organisation. He had been detained in Arauca prison for more than six months, accused of rebellion. During a meeting with the Colombian President we highlighted Martin's case and, to my delight, days later he was freed and all charges dropped.
This clearly demonstrates the absurdity of the situation - a man was released who we had been assured was a dangerous terrorist - but it also proves that international pressure on the regime really does make a difference.
It is vital that international pressure is increased. I urge everyone who values human rights and academic freedom to contact their MP and write to the Colombian ambassador to convince the Colombian authorities that jailing people is not an acceptable way of treating critics. Hopefully, this injustice will then be brought to an end and Dr Beltran can finally accept the UCU's invitation to speak to his colleagues in the UK.