Britain will introduce measures to counter Islamist extremism, including an investigation into Sharia courts and a crackdown on incendiary preachers, if Prime Minister David Cameron's Conservatives win May's election, Home Secretary Theresa May said on Monday.
May said Britain would no longer tolerate those who rejected the country's values of democracy, free speech, equality and the rule of law, adding that Islamist extremism presented the most serious and widespread problem.
"To those who choose consciously to reject our values and the basic principles of our society, the message is ... clear: the game is up," she said in a speech in London. "We will no longer tolerate your behavior."
Britain has wrestled with how to deal with extremism and radicalization among its 2.8 million Muslims since the Sept. 11, 2001, attacks on the United States.
The issue came to the fore after suicide bombings on the London transport system in 2005 and the murder of a British soldier in 2013 by young British Islamists, while recently some 600 Britons have traveled to fight in Iraq and Syria including "Jihadi John", suspected of being the most notorious executioner of Islamic State radicals who have occupied swathes of Iraq and Syria.
May said not all extremism led to terrorism, but that those who spread hatred had to be tackled and she called for Muslims to join "a partnership" to defeat extremists.
Measures she said would be brought in under a Conservative government included bans for groups which fell short of current terrorism proscription orders, closure orders to shut down premises owned or used by extremists and extremism disruption orders to target individuals who incite hatred.
There would also be an independent figure commissioned to investigate the use of Islamic law by Sharia councils, used to settle family and inheritance disputes by some British Muslims.
The Conservatives have already pledged to beef up security measures as part of their commitments ahead of the May 7 general election, which pollsters say could be one of the closest for decades.
Recognising that there were those who disagreed with her approach, May said she wanted to defeat all forms of extremism, including far-right ideology, and that promoting British values was not narrow-minded or jingoistic.
"The starting point of the new strategy is the emphatic rejection of the misconception that in a liberal democracy like Britain, 'anything goes' -- the belief that living in a society like ours means there aren't really any fundamental rules of norms," she added.