THERESA MAY last night revealed security services are running 676 ‘live’ counter-terror investigations - as she urged Brits to come together to defeat “twisted” extremists.

The PM spoke of her “shock” at the second attempt on Westminster in as many years.

And Downing Street said the number of live counter-terror investigations had leapt from “more than 500” in March 2018 to the astonishing figure of 676.

The security services have foiled 13 Islamist plots in the past 18 months and 4 by far-right extremists.

The PM was informed of yesterday’s attempt within minutes of the terror suspect driving his Ford Fiesta into crash barriers outside Parliament.

After spending the morning locked in talks with officials from her break in Switzerland – the PM said: “The threat to the United Kingdom from terrorism remains severe.

“I would urge the public to remain vigilant – but also to come together and carry on as normal, just as they did after the sickening attacks in Manchester and London last year.

“The twisted aim of the extremists is to use violence and terror to divide us. They will never succeed.”

She also praised the “formidable courage” of the emergency services.

“Once again, they did not flinch and ran towards a dangerous situation in order to protect the public. The country is hugely grateful for their calmness and professionalism.”

Last night Security Minister Ben Wallace said the suspect was in his late 20s, British and originally from another country.

The PM is on the second leg of her summer break with husband Philip.

Yesterday’s attack took place with the Palace of Westminster, down to a skeleton staff during ‘recess’.

The government’s COBRA emergency committee met to consider the situation at 2pm – but no ministers were present.

In the PM’s absence, Chancellor Philip Hammond is the ranking minister on duty in Westminster.

No.10 said Home Secretary Sajid Javid was delaying a family holiday to be kept abreast of developments in London.

Tory backbencher Nigel Evans – one of the few MPs still in London – said it was time to consider pedestrianising the area around Parliament.

He told Talkradio: “I suspect this will reignite debate as to whether the whole of Parliament Square should be pedestrianised to ensure nobody can weapon a vehicle and attempt to disrupt and indeed destroy our democracy.”

The PM’s spokesman played down the idea and insisted security measures “worked today”

In her statement, Mrs May said her thoughts were with the “innocent members of the public” who were hurt. She said: “Today’s attack outside the Houses of Parliament is shocking.

“For the second time in as many years the home of our democracy, which is a potent symbol of our precious values of tolerance and freedom, has witnessed terrible scenes just yards from its door.

“’My thoughts are with the innocent members of the public who were hurt in this appalling incident. I wish them a speedy recovery and we must be thankful that nobody suffered life-threatening injuries.”