Media unions have condemned a video in which kidnapped British photojournalist John Cantlie delivers a message under duress in what he admits is an attempt to save his life.

In statement made before the release on 23 September of a second video featuring the journalist, Michelle Stanistreet, general secretary of the UK journalists’ union NUJ, said: “It is outrageous that a journalist who went to Syria to do his job, reporting on an unfolding crisis and its devastating impact on its citizens, was kidnapped and has been held now for two years.”

It is believed John Cantlie has been held hostage by Islamic State (ISIS) militants since his kidnapping in Syria in 2012.

“This video, in which John has been forced to deliver a message on behalf of ISIS knowing that his life is on the line is yet another disgraceful and cowardly attempt to target and intimidate reporters from carrying out their work. Its intention is clear, to spread fear and to send a message that journalists – along with other workers – are fair game and mere political pawns to be exploited as their captors see fit,” Michelle Stanistreet said.

Jim Boumelha, president of the International Federation of Journalists (IFJ) said: “It is absolutely appalling that our colleague John, a journalist who was carrying out his job, has first of all been held captive for two years and is now being used as a propaganda tool in the political game being played by his captors.

“We repeat our demand for urgent international action from governments across the world to protect journalists reporting in Iraq and Syria who are courageously risking their lives to ensure the stories and hardships of people caught up in this conflict are told. Enough is enough – journalists must be free to report the truth and cannot be used as weapons of war.”