Why I say no to 42-day detention, by Muslim Met chief

Met Assistant Commissioner Tarique Ghaffur has told friends he fears the new limit would be "counter-productive" and harm the long-term battle to combat radicalisation in Islamic communities.

He believes there is "no evidence" to support an extension to the detention period of 28 days.

Friends say Mr Ghaffur, who is responsible for liaising with Muslim communities in London, cannot speak out publicly because his views contradict those of Met chief Sir Ian Blair.

Today's disclosure will be a blow to ministers, who are already facing the prospect of a Commons defeat over the plans amid opposition from Labour backbenchers, the Tories and Lib-Dems as well as civil liberties campaigners.

Director of Public Prosecutions Sir Ken Macdonald has also questioned the need for the 42-day time frame and Justice Secretary Jack Straw is reported to have doubts about the proposals.

The Association of Chief Police Officers has backed the plans put forward by Home Secretary Jacqui Smith.

The Standard has learned Mr Ghaffur is particularly concerned about the danger of the extended limit fuelling a sense of grievance and resentment among some Muslims and undermining efforts to tackle the spread of radical views.

He has told others: "A 42-day limit will be counter-productive. There is no evidence to support it and the danger is that it will make the police's long-term job harder."

It is understood he shares the view of the Government and Sir Ian about the growing complexity of terror plots and the increasing threat posed by the spread of radicalisation.

He believes Muslim leaders need to speak out more strongly against extremist views. But he fears controversy over the 42-day detention period will make this less likely and allow support in Islamic communities for extremism to grow by portrayals of themselves as victims targeted unfairly by the authorities. This will make it harder for police to obtain intelligence and support from the communities, says Mr Ghaffur.

This week, Ms Smith emphasised that countering radicalisation was the Government's top priority. She repeated a warning by MI5 director general Jonathan Evans that the threat posed by al Qaeda-inspired terrorism is growing.