Conservative leadership hopeful David Cameron has likened Islamist extremists to Nazis and has warned that failing to confront them will be fatal.
David Cameron called for a Muslim commission to regulate mosques
The shadow education secretary says the rise of Hitler showed that a willingness to give ground and avoid confrontation was seen as weakness.
In a Foreign Policy Centre speech, he also said more needs to be done to ensure all Britons can speak English.
Mosques should be regulated to tackle extremists, Mr Cameron added.
Other measures he has urged include a dedicated border police force and 24-hour security at major ports.
He argued that schools which receive government funding should teach in English.
He also said Britain should withdraw entirely from international human rights conventions if they prevent the deportation of Islamic radicals.
And he warned a strain of Islamist thinking had developed which, like Nazism and Communism, offers followers redemption through violence.
"Just like the Nazis of 1930s Germany, they want to purge corrupt cosmopolitan influences," he said.
But those remarks prompted criticism from the Islamic Human Rights Commission.
"For such a comment to be made against any community is outrageous, but even more so when those labelled are the greatest victims of Nazi-style oppression today," the IHRC said.
In his speech, Mr Cameron also argued that the West's failure to act in the 1990s fed Osama Bin Laden's belief that it lacked the strength to defend itself.
"The lesson from all of this with respect to our presence in Iraq is clear.
"Premature withdrawal - and failure to support the Iraqi authority - would be seen as a surrender to militant Jihadism. Nothing would embolden the terrorists more."
Mr Cameron told BBC Radio 4's Today programme that tackling the threat of fundamentalist Islamist terrorism was "the most important issue facing the country".
He said he had discussed his proposals with rival Tory leadership contender David Davis, the shadow home secretary.
"We have got to work out very clearly what we do in foreign policy terms, in domestic policy, in terms of anti-terror laws, and also what we do to bring this country together at this time," he said.
"It is right that people who are debating the future of this country and the future of the Conservative party, make their views known."
BBC News political correspondent James Landale said that while Mr Cameron supported much of what the government was doing to combat extremism, he was sending a clear signal that he could be tough on terrorism too.
Mr Cameron also told the Today programme that he was not interested in deals or dream tickets with any of his potential rivals for the party leadership.
That followed a renewed burst of speculation that he might team up with ex-chancellor Ken Clarke.