A Conservative government would ban extremist Islamist groups, refuse visas to hate preachers and insist that universities identify and root out radicals promoting violence, antisemitism and other racial intolerance on campus.

In an exclusive interview with the JC, Conservative leader David Cameron said his party would "drain the poison" of extremism. He said recent visitors to Britain such as Yusuf al-Qaradawi, the influential Egyptian cleric who supports suicide bombing against Israeli targets, and Ibrahim Moussawi, Hizbollah's "media relations officer", would never again be allowed into the country.

He also confirmed that a Tory government would ban the virulently anti-Zionist group Hizb-ut-Tahrir, which calls for the re-establishment of the caliphate (Islamic state).

While defending the principle of academic freedom, he said universities had a responsibility to root out extremism, even if this meant fingering individual students for their beliefs: "That means making clear to university authorities and student unions that they need to help identify those who are vulnerable to influence from extremists or show they are willing to promote hatred, just as they would in relation to any other suspected crime," he said.

The Tory leader was scathing about Gordon Brown's pledge to change the law that allows senior Israelis to be arrested for alleged war crimes in Britain.

The truth is that we would never ally with a party we believed to be antisemitic

"I think the government's approach to this has been feeble," he claimed. "They said back in December that they would look at changing the law to stop political groups being able to issue private arrest warrants - but we're now just weeks away from an election, and still nothing has been done.

"It's a big problem. It means that while we're saying we want to get the peace process moving and that we want Britain to play a part in that, some of the key people we need to talk to in Israel are being deterred from coming here. It puts us in a really weak position. We will keep pressing the government to make this right - and if they don't, we will."

He also pledged action following the Supreme Court decision on JFS, which found that admissions made on the basis of parental Jewish descent breached race relations legislation.

"We are talking to lawyers about this case and about what it means for the future. We're going to look into this very closely indeed," he said.

Mr Cameron said he had serious concerns about some conclusions of the Goldstone Report on the Gaza conflict. "The detailed allegations of human rights abuses… are serious and they do need to be fully investigated." However, he confirmed that a Conservative government would have voted against the UN Human Rights Council Resolution on the report because it "didn't mention Hamas's role in starting the conflict".

The Tory leader remained resolute over his decision to ally himself with partners in the European Parliament accused of extreme-right sympathies and antisemitism.

He defended the reputation of Polish MEP Michal Kaminski, leader of the European Conservatives and Reformists group, of which the Tories are members.

He said: "The Chief Rabbi of Poland has himself made it very clear that the Polish Law and Justice party is a mainstream party and their MEP Michal Kaminski, who has been the focus of Labour smears, is not only not antisemitic, but actually has a record of combating antisemitism."

He added: "The truth is that we would never ally with a party we believed to be antisemitic, led by antisemites or with links to the far right. I hope Jewish Chronicle readers can see that."

Mr Cameron said he was proud that the Tory party had produced Britain's first ethnically Jewish prime minister in Benjamin Disraeli and the first practising leader of the Opposition in Michael Howard.

"We can't ever be complacent," he said. "But if you look at our party today you see we've got a Jewish chief executive, Andrew Feldman, we've got a Jewish chairman of the Research Department, Oliver Letwin, and at this general election we'll have Jewish people standing as Conservative candidates in really winnable seats.

"I didn't do this, the Conservative Party did it, and I'm really proud of the way we've shown we can change."

The Interview in Full: Only on TheJC.com - read it here.