Boris Johnson has said he wants to scrap the Tpim terrorism prevention system introduced by the coalition and bring back Labour's control orders - however the Tory mayor repeatedly failed to explain what the acronym 'Tpim' actually stood for.
For the record, the the policing mechanism introduced by home secretary Theresa May are known as Terrorism Prevention and Investigation Measures.
Tpims replaced control orders in 2011. The coalition said the idea was to replace control orders with a "more focussed and less intrusive system of terrorism prevention".
However the security and intelligence services have faced questions over the monitoring of terror suspects following the unmasking of the Islamic State extremist Mohammed Emwazi, who was known as "Jihadi John".
Speaking on LBC radio this morning, Boris said Tpims "don't work and they need to be replaced". He added: "What we need to do is go back to control orders."
However pressed to explain what Tpims actually were, he fumbled. "Temporary… I can't remember," he struggled. "I cannot remember what a Tpim is, whatever it is, it's inadequate".
When host Nick Ferrari questioned whether the mayor should know what something was before calling for it to be replaced, Boris told him to stop asking "silly smart-alec questions".
Boris' call for the return of control orders is also at odds what he said in 2005. Then the MP for Henley, Boris said control orders were a "cynical attempt to pander to the many who think the world would be a better place if dangerous folk with dusky skins were just slammed away".
Writing in The Daily Telegraph he said:
The more I listen to Labour ministers on this subject, the more I suspect that control orders have been pushed to the fore as an electoral device, to neutralise the advantage the Tories have claimed on asylum. It is a cynical attempt to pander to the many who think the world would be a better place if dangerous folk with dusky skins were just slammed away, and never mind a judicial proceeding; and, given the strength of this belief among good Tory folk, it is heroic of the Tories to oppose the Bill. We do so because the removal of this ancient freedom is not only unnecessary, but it is also a victory for terror.