More than 500 pro-animal testing campaigners marched through Oxford city centre on Saturday.
The demonstration, organised by Pro-Test, the group supporting the construction of Oxford University's animal research lab, saw protesters gather in Parks Road shortly before noon on Saturday for a rally.
Brandishing placards reading "Support Our Scientists" and chanting "Human beings come first, build the Oxford lab", they marched along Catte Street, High Street, Longwall Street and Holywell Street before ending the demonstration in South Parks Road outside the partially-built £20m laboratory site.
Pro-test founder Laurie Pycroft, a 16-year-old from Swindon, led the march alongside MP for Oxford West and Abingdon Dr Evan Harris, MP Alan Duncan and neurosurgeon Tipo Aziz.
He said: "I'm very pleased with the way the march went. It's brilliant to see so many people enthused and supportive.
"There's definitely been a change in public opinion. We're really making a difference."
David Priestman, a scientist at Oxford University's pharmacology department, took part in the march. He is currently working on projects looking at genetic disorders in children, which involves testing on humans and mice.
Dr Priestman said: "I have worked in animal research for nearly 30 years and at last I can speak out about what I do. I'm exceptionally proud of my work. What right have animal rights activists to say my work is not scientific?
"I am totally passionate about my work. I want to move my research into the new lab. We want to see it built.
"There used to be a desperate climate of fear, but the animal rights' activists don't intimidate me. I'm not frightened at all."
Dr Priestman marched with his father Michael and mother Mary, who is in a wheelchair and said: "I would not be here if it wasn't for drugs. Animal research has helped find treatments."
Also marching was 18-year-old student Georgie Day, who had travelled to Oxford from London for the event.
She said: "The Pro-Test group is making progress all the time. More and more people are realising their arguments make sense. Everyone here is marching for progress. It's a case of putting people first."
Ken Brownsey, a computer scientist at Oxford Brookes University, also took part.
He said: "We all owe something to medical research so I am marching not only for that but to show solidarity for fellow university workers."
Thames Valley Police estimated between 500 and 600 people took part in the demonstration. A spokesman said: "We are happy with the way the march was carried out. Everything went to plan and discussions held beforehand meant it all went smoothly."