A millionaire who pelted the Prime Minister with flour bombs has walked free from court with a £600 fine.

Guy Harrison, 36, said the conviction could prevent him from pursuing business interests in the United States.

But he said he had no regrets about the attack on Tony Blair which has led to a full review of security in the Commons.

Harrison, of Sopers Farm, Peppers Lane, Ashurst, near Steyning, admitted flinging three condoms filled with cornflour during Prime Minister's Questions last week.

Harrison made millions as a farmer and property tycoon and includes a children's nursery among his extensive assets.

He was protesting as a member of the radical campaign group Fathers4Justice, who are using headline-grabbing techniques in their attempt to win equal rights for both parents of a child in the family courts.

He told The Argus: "Getting a criminal record makes a huge difference to my business commitments.

"I may have difficulty getting into the United States. I have no idea how much this will cost me.

"But my daughter is much more important to me than any business interests I may have around the world.

"I have mixed feelings about the sentence. It's not as lenient as it could have been but we did breach Westminster security and put everyone on high security alert.

"It shows the society we live in when you can use a condom filled with flour on the Prime Minister more easily than you can get access to your own children."

Harrison admitted the stunt had done nothing to help his own case in trying to gain access to his daughter.

He said: "There has been no improvement. I've not seen my daughter for three years.

"I own one of the largest nursery schools in the South of England but I am treated like a paedophile with my own child."

He vowed to take part in further direct action protests with Fathers4Justice.

He added: "They have given me a criminal record for life so there is not much more they can do to me apart from put me in prison. We started out low with the Houses of Parliament and now we are going for the top."

Bow Street magistrates were told Harrison gained access to the VIP section of the public gallery in the Commons on May 19 after winning a raffle at a charity auction.

He stuffed the flour-filled condoms down his trousers to avoid detection by security.

During Prime Minister's Questions Harrison stood up and lobbed the bombs 40ft over the railings, hitting Mr Blair's back. After his arrest, he immediately admitted throwing the bombs and told police they were filled with dyed flour.

Harrison pleaded guilty to using threatening words or behaviour.

Hugh Davies, defending, said: "This was a desperate measure by a respectable man unable to come to terms with the circumstances in which he has lost contact with his daughter.

"He has made his point and he now wishes to move on.

"Although arrested and interviewed under the Terrorism Act, his actions were not intended to be more than the actions of a streaker at a cricket match."

The solicitor said Harrison was motivated by "the ordinary, simple human desire to restore contact with his own daughter and to promote the interests of other fathers in his position."

District Judge Timothy Workman told Harrison as he passed sentence: "By your action you deliberately disrupted Parliament and, in the present climate, caused considerable alarm and anxiety to many people.

"I consider you fortunate not to have been charged with a more serious offence."

New security measures at the Commons were announced yesterday. Speaker Michael Martin suspended the right of MPs to bring guests into galleries not protected by a new £600,000 screen until further notice. Only people personally invited by him would be allowed in the area in front of the screen.

He said: "I am sure the House will appreciate that it is in the interests of all those who work in this building that the lessons of last week's incident are learned and acted upon."

Ron Davis, 48, of Vale Avenue, Worthing, has pleaded not guilty to using threatening words or behaviour. A trial date will be set next month.