Sadiq Khan has said London will “never be cowed by terror” as the capital mourns the death of three victims in the Westminster attack.

“You will see Londoners returning to work whether it’s in Parliament, whether it’s in City Hall, whether it’s in hospitals or businesses across London, because that’s who we are,” the mayor told BBC Radio 4's Today programme.

“We are not going to allow these terrorists to cow us, we’re not going to allow them to change our way of life.”

Mr Khan paid tribute to PC Keith Palmer and other victims of the attack, which saw a man plough his car into pedestrians on Westminster Bridge, killing two members of the public.

He crashed it into a fence outside the Houses of Parliament, launching himself inside the entrance and fatally stabbing PC Palmer before being shot dead.

The Metropolitan Police is deploying extra armed and unarmed patrols across London to provide protection and reassurance in the aftermath of the atrocity, which investigators are treating as an Islamist-inspired terror attack.

Mr Khan praised the emergency services for carrying out their work in “extremely difficult circumstances”, with concrete bollards among the safety measures being deployed.

In pictures: Westminster attack Show all 9 1 /9 In pictures: Westminster attack In pictures: Westminster attack An air ambulance lands after gunfire sounds were heard close to the Palace of Westminster in London PA wire In pictures: Westminster attack MPs wait until the situation is under control in Westminster. 'The alleged assailant was shot by armed police,' David Lidington, leader of the House of Commons, told the house. BBC News In pictures: Westminster attack Crowds gather in Westminster after shooting incident, which police are treating as terror attack BBC News In pictures: Westminster attack Police were also called to an incident on Westminster Bridge nearby AP In pictures: Westminster attack Early reports indicate the car, which mounted the pavement on Westminster Bridge and mowed into around a dozen people, was the same vehicle which then rammed into the railings of the Palace of Westminster, just around the corner Reuters In pictures: Westminster attack Security sources described the suspected assailant as a middle-aged Asian man, who is understood to have left the car before attacking a police officer with a seven-to-eight inch knife PA wire In pictures: Westminster attack Police have asked people to avoid the immediate area to allow emergency services to deal with the ongoing incident AP In pictures: Westminster attack One woman has died and a number of others, including the police officer, have been hurt, according to a junior doctor at St Thomas' Hospital Reuters In pictures: Westminster attack At least three gun shots were heard by those inside Westminster, and proceedings in the House of Commons have been suspended AP

He has come under fire over an interview last year where he said the threat of terror attacks were “part and parcel of living in a big city” and said security services had to be prepared.

“We’ll take the precautions we’ve got to take but remind the world that London’s faced such horrific incidents before,” the mayor and former Tooting MP added.

“We can’t allow them to succeed in dividing communities, we will not allow them to destroy our way of life.

“We’re going to be defiant, we’re going to be resilient, we’re going to return to work but of course never be complacent…we must never accept terrorist being successful.”

The mayor also urged the UK not to allow the attack to be used as a means of inciting hatred.

“Terrorists want to attack London is because they hate the fact that we don’t just tolerate each other – whether you’re a Christian, Muslim, Jew, Hindu, Sikh, Buddhist, member of an organised faith or not, we respect, embrace and celebrate each other and that’s going to carry on,” he added.