When he joins in mid-February, Wren can expect to handle comms around provocative issues including terrorism, immigration, the reform of the police service, drugs, crime, prisons and anti-social behaviour.
He will also be charged with communicating the launch of the Serious Crime Agency in April. The agency is being set up to tackle
organised crime and brings together law enforcement agencies such as the National Crime Squad and the National Criminal Intelligence Service.
Reporting to Home Office head of comms and Whitehall stalwart Julia Simpson, Wren will lead a team of 50 press officers.
He joined the MoD just nine months ago, taking over from Pam Teare, a key witness in the Hutton Inquiry and author of the controversial Q&A briefing that led to the naming of Dr David Kelly (PRWeek, 23 April 2005).
His departure comes shortly after a document leaked to a national newspaper showed the extent to which military commanders were concerned about the effect of bad publicity on morale in the armed forces. However, the move is not believed to be connected.
'The challenge of my role is to communicate how we try to bring peace and stability to hot spots around the world. Negative coverage of this is very hard to deal with,' said Wren.
He added that the MoD is in the very early stages of finding his replacement.
Before the MoD, he was acting comms director at the Department for Transport.