'It is not the police, it is not the intelligence services who will defeat terrorism, it is communities who will defeat terrorism,' the Commissioner told a gathering at the Minhaj-ul-Quran Mosque in south London.
'I need you,' he continued. 'We've got nearly a million Muslims in London... I've only got 300 Muslim police officers in London. I'm afraid that's not good enough. I need your mothers and your fathers, your brothers and your sisters, your sons and your daughters.'
Another Muslim group, Minhaj-ul-Quran International UK, said the mosque should have been a community project rather than a proposal by an individual group.
A spokesman, Shahid Mursaleen, said "If the mosque is built with the consensus of the community then it will appeal to people of different faiths instead of just for Muslims.
"We urge the Newham community to unite and support this as a 'community project' so that it can be ready for 2012."
But Muslim campaign group Minhaj-ul-Quran UK said the government had done the right thing.
"We support the ban on the extremist groups but suggest banning extremist individuals too as they will appear again with a different name," said spokesman Shahid Mursaleen.
"We have always supported the idea of banning extreme individuals and extremist groups from working in this country and have for a very long time been frustrated that they have been allowed to infiltrate universities and mosques to promote a message of hatred with their anti-West agendas," said spokesman Shahid Mursaleen.