A leading Muslim in Britain has warned authorities against helping to create a climate of fear and suspicion similar to that in Nazi Germany during the 1930s.

The government's policy of emphasising the threat from al Qaeda is alienating many Muslims and undermining social cohesion, Muhammad Abdul Bari, head of the Muslim Council of Britain, said.

"The air is thick with suspicion and unease. It is not good for the Muslim community, it is not good for society."

He suggested the British government and MI5 were helping create an atmosphere of exclusion with their rhetoric.

"Every society has to be really careful so the situation doesn't lead us to a time when people's minds can be poisoned as they were in the 1930s," he said in an interview with The Daily Telegraph.

The new head of MI5, Jonathan Evans, said last week militant Islamists were growing in number and were targeting children as young as 15. Bari said he thought Evans' speech was "creating a scare in the community and wider society".

"It probably helps some people who try to recruit the young to terrorism," he said. "There is a disproportionate amount of discussion surrounding us.

"If your community is perceived in a very negative manner, and poll after poll says that we are alienated, then Muslims begin to feel very vulnerable."

The MCB is an umbrella organisation with 500 affiliates.

It has called for improved ways of working with the police to try and prevent terrorist attacks. Its hardline members have been criticised by some, including the Conservative Party, of harbouring and even promoting militant views.

Sir Paul Lever, former chair of the Joint Intelligence Committee, said talk of the security threat was not exaggerated and described the figure of 200 people having been convicted for terrorism as alarming.

"We need to keep it in proportion, we need to take care in our public discourse that we do not demonise all Muslims," he told BBC radio.

"But equally, we mustn't get into the state where we are so fearful of offending people that we are unwilling to talk about what are, sadly, very worrying facts."

Bari said Britain could learn from aspects of Islamic culture such as arranged marriage, modesty, limits on alcohol, tighter abortion laws and sexual restraint.

"Everyone can learn from everyone. Some of the Muslim principles can help social cohesion -- family, marriage, raising children with boundaries, giving to the poor, not being too greedy," he said.