Despite all my years and experience of protests, nothing quite prepares you for how it feels to be arrested. I was far more upset than I thought I would be; in that moment you suddenly feel as if you have absolutely no power. This was the first time I’ve been arrested. I like to think I’m a law-abiding citizen, I don’t drop litter, run red lights on my bike, or take backhanders to lobby on behalf of dodgy corporations.

I originally went along to the Occupy camp in Parliament Square to bring the protesters some tea in a Thermos, and I was booked in to speak there about policing and civil liberties. On Tuesday morning, though, I hadn’t been demonstrating, I had come to visit the camp because I was concerned about reports of over-policing. I saw an old friend of mine being arrested and thought he seemed upset and distressed. I was holding on to and comforting him, he was shaking and I was hugging him. But the police pulled me off and arrested me – letting me go five minutes later once they had enough details for them to proceed with a summons. Or as some have cynically suggested: once they discovered who I was.

People may scoff at the aims of the Occupy movement. You can question the point or success of camping outside parliament, but don’t question their sincerity. Having spent a night camped outside St Paul’s cathedral with Occupy back in 2011, I can say it is not a pleasant experience being outside in uncomfortable, often cold, conditions. The people camped outside parliament are dedicated and care passionately about fighting injustice, inequality and for a better society that puts people, democracy and the environment before profit. I will defend their right to do that outside parliament just as I defended the Countryside Alliance’s right to protest against the fox-hunting ban outside parliament. I often don’t agree with a lot of what some protesters say, but as long as it is non-violent, I will defend their right to say it.

Police remove a protester from Parliament Square Photograph: Steve Parkins/Steve Parkins/Demotix/Corbis

I find it shocking how many activities are prohibited in Parliament Square unless authorised: operating amplified noise equipment, erecting a tent, or any other structure designed or adapted for the purpose of facilitating sleeping or staying in a place for any period. I cannot believe someone can be arrested for holding up a piece of plastic, or two people arrested for passing a bottle of water to a fellow protester.

The prohibition of “unauthorised” activities in Parliament Square is just part of the creeping trend towards the private control of public space, which can lead to excessive restrictions or exclusion. The Antisocial Behaviour, Crime and Policing Act further expanded the powers of councils and the police to control who can do what in public space. The private and state restrictions on public space are hardly in the spirit of democracy and inclusion. They undermine the idea of public space that is open, accessible and free to enjoy.

The police have a duty to facilitate peaceful protest in this country which people have a legal right to do, but that appears to end as soon as you come within shouting distance of the Westminster village. It’s a pity that a peaceful protest drawing attention to the inequality in our society is not allowed to continue. Democracy and protest can be messy and inconvenient, but they are essential to having a free society and should not be hidden away to spare the discomfort of those in power. The people who run this country should not be able to tuck demonstrators away out of sight. Since my arrest, I have been asked how this would go down in the House of Lords. Colleagues and the public have been very supportive – although one peer did tell me that at my age I was too old to be at protests like this. But the reaction of others to my arrest is the last thing I am thinking about. My thoughts are with the others who were arrested but not so fortunate to be “de-arrested”. They were only trying to make their voices heard.