A fathers' rights campaigner sparked a security alert when he climbed on to the roof of Parliament.

Guy Harrison, from Ashurst near Steyning, who was fined for his involvement in the powder-bombing of Tony Blair in the Commons chamber a year ago, scaled the historic Westminster Hall yesterday.

Mr Harrison, who is 38 today, said his protest in the name of pressure group Fathers 4 Justice was a birthday present for his seven-year-old daughter, whom he has not seen for four and a half years.

Mr Harrison, said to have earned his wealth through his property dealings and believed to be going out with pop star James Blunt's sister, climbed out of a window while visiting an exhibition.

He clambered down 60 feet and then climbed 300 feet up on to the roof.

Mr Harrison said: "We've been in dialogue for nine months with Government bodies and we hoped we would receive more cooperation than we have.

"The last thing we want to be doing is scaling this massively high, extremely windy place to get our stories across.

"I can't think of anything worse than doing this, it's terrifying. I've never climbed up high like this before."

He told reporters from the rooftop: "I can see armed police down there, that doesn't instill me with a lot of confidence.

"I hope they know I'm not Brazilian."

He said he hoped his actions would remind his daughter how much he loved and missed her.

Asked how long he would stay on the roof, he joked: "About six to eight months."

Then he added: "I suppose until later on today."

In September last year, a court heard how Mr Harrison threw three condoms filled with purple flour into the House of Commons chamber, hitting Tony Blair in the back during Prime Minister's Questions.

He staged the protest with fellow campaigner Ron Davis from Findon.

The stunt prompted police to evacuate the chamber, thinking it was a terrorist attack.

Harrison said he had been denied access to his daughter and wanted to highlight the lack of access rights for fathers.

His latest stunt prompted an MP to call for a security review at Westminster.

John Hemming, Liberal Democrat MP for Birmingham, Yardley, said: "It does cause some concern that someone should be able to break security twice.

"I am calling for a review to see whether there can be a technological solution to scan and recognise the faces of people who have a track record of doing things like this."

Mr Harrison's action was timed to coincide with the Prime Minister's address to the Labour Party conference in Brighton and is the latest in a series of security scares at Westminster.

As well as Mr Harrison's previous brush with the law, pro-hunting campaigners stormed the Commons chamber last year during a debate on the Fox Hunting Bill.

Greenpeace supporters also scaled Big Ben in a protest against the Iraq war.

This time Parliament was in recess so there were few MPs around.

Mr Harrison came down from his perch just after 8pm - five hours after he climbed on to the roof.

He rolled up his banner, which read "Does Blair Care", and clambered down the stonework on to a turret where he was met by police officers.

A police spokeswoman said Mr Harrison was arrested for aggravated trespass and taken to Charing Cross police station for questioning.

Another Fathers 4 Justice member was driven away in an ambulance after slipping on the pavement following a scuffle with police.