The Prime Minister has said the “Islamist” attack on Parliament was not “Islamic” and Islam is a “great faith”.

Taking on the role of a theologian, Theresa May insisted: “It is wrong to describe this as Islamic terrorism. It is Islamist terrorism. It is a perversion of a great faith.”

Speaking in Parliament, she also said the attack showed “the importance of all of our faiths working together, and recognising the values that we share”.

Adding: “This act of terror was not an act of faith. It was a perversion; a warped ideology, which leads to an act of terrorism like that and it will not prevail.”

Islamism is generally defined as a political interpretation of Islam. Some critics argue Islam is intrinsically political – as the Quran mandates a religious state and law – and say the term is irrelevant.

MPs almost unanimously agreed with the Prime Minister, lining up to warn against “demonising” and “stigmatising” Muslims, and to condemn “Islamophobia” and “racial and religious” discrimination.

Khalid Mahmood, the Labour MP for Birmingham Perry Barr, said the attacker or attackers “pretend to be of a particular religion”.

“If they were of a religion they would not be carrying out acts like this,” he added.

Tulip Siddiq, the Labour MP for Hampstead and Kilburn, added: “People who commit acts of terrorism in the name of Islam do not speak for the majority of Muslims in this country.”

UKIP leader Paul Nuttall, meanwhile, did not shy away from describing the attack as “Islamic”.

“We have a cancer within a particular community and it needs to be cut out,” he told Sky News outside Westminster Palace. “The Muslim community I believe needs to do more about this.

“We have the problem that we have 800 British citizens out fighting in Syria and Iraq for Islamic State.

“I don’t believe they should be allowed to return and I think that, down the line, we’re going to have to look at foreign funding of mosques, particularly from Saudi Arabia, who promote radicalism across the globe.”