In news that will surprise nobody, violence again marred an anti-austerity protest in central London tonight with one MP accusing demonstrators of forming a "murderous mob".

Ukip MP Douglas Carswell said he genuinely feared for his life after being surrounded by protesters as he tried to leave Westminster following the Queen's Speech.

Mr Carswell said the group that shouted abuse at him as he waited for a bus appeared to have "pretty murderous" intent before he was escorted by officers into the back of a police van as demonstrations turned nasty.

Warning: Language in video below.

He was caught up in one of several violent flashpoints as hundreds of people joined the protest, which began in Trafalgar Square, after the Queen's Speech outlined the new Conservative government's plans.

There were skirmishes with police as protesters - some wearing masks and scarves to cover their faces - ran down Whitehall.

Uniformed police linked arms to form a human barricade to try to contain the protesters and some pulled out their batons to warn off demonstrators.

Ex-Tory Mr Carswell - his party's only MP - said he had been engaged in peaceful discussions with a small group before being confronted by far larger numbers shouting insults such as "Ukip scum".

He said: "It got extremely, extremely nasty. Their intentions were pretty murderous and I needed a lot of police officers to prevent them from attacking me.

"I was stunned. I think MPs should be able to go about their business. It was incredibly intimidating. It was like a lynch mob on the streets of London. I thought this was a country where we had democracy and discussed the issues.

"It just got incredibly ugly. It was an attempted lynching. I am in a state of shock. I do not want to have to worry about going about my business."

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The MP added: "If the police had not been there I do not think I would be here now my safety was very, very seriously at risk. I have never seen such hatred.

"If this is the way the extreme left behave now, I do not think it bodes well for the future."

Elliot Corner, 20, who studies classical music at the Royal College of Music in London, was peacefully protesting in Trafalgar Square.

He said: "We are here today because we believe that austerity is a failed economic measure and transfers wealth from the poor to the rich.

"We believe the new cuts that are planned by George Osborne are completely unfair and unwarranted."

Scotland Yard said that by 10pm there had been five arrests.

A 17-year-old youth was arrested on suspicion of assault on police.

A man was arrested on suspicion of violent disorder and possession of an offensive weapon.

Another man was arrested on suspicion of violent disorder at Brixton Town Hall on April 25.

And two men were arrested on suspicion of violent disorder at an earlier protest on May 9 in Whitehall.

All were taken to central London police stations where they remain in custody.

Business secretary Sajid Javid condemned what he called on Twitter the "outrageous attack by mob on Douglas Carswell".

"No respect for democracy and freedom of speech," he complained.

Tory MP Zac Goldsmith denounced the "chilling scenes of a hate mob attacking ... one of our democracy's fiercest champions".

Political blogger and columnist Harry Cole, who had been chatting with Mr Carswell when the crowd gathered, said he had "no doubt that crowd would have turned violent had the police not stepped in".

He said: "Carswell was a gent and tried to reason with the mob. If only these people knew of his disdain for the elite."