Joan Court (left) is going without food or shelter for 48 hours

Joan Court is in an upbeat mood and delighted by support from passers-by, according to a fellow campaigner.

Ms Court, from Cambridge, began her 48-hour hunger strike at 1000 BST on Wednesday in South Parks Road, Oxford.

Oxford University says the �18m centre will replace existing sites and does not mean an increase in animal tests.

A group of eight supporters, including a nurse, are taking turns to keep Ms Court company.

The weather could be nice, but she is very upbeat, especially with the reaction from passers-by Robert Cogswell, supporter

Before starting her protest, the retired midwife and social worker said she was inspired by Ghandi's hunger strikes against British rule of India.

Robert Cogswell, a spokesman for animal rights group SPEAK, told BBC News Online: "At the moment she is bearing up very well and getting a lot of support from local people.

"The weather could be nicer, but she is very upbeat, especially with the reaction from passers-by and after receiving floral bouquets from national organisations wishing her luck.

"We have taken great pains to keep her safe and well.

"If there are any problems we will call it off, but we aren't expecting anything as she is a very sprightly 85-year-old."

When it is essential to use animals, we ensure that they experience the highest standards in animal welfare Oxford University spokesperson

Ms Court is expected to be the star speaker at a demonstration in Oxford on 24 July against the proposed centre.

Some 98% of the animals there would be rodents, although the centre could also house ferrets, amphibians, fish and primates.

She said: "Gandhi influenced me a great deal when I was younger - at the time, he was bringing down the British Empire in India with hunger strikes.

"I don't think we can bring down the vivisection industry, but we can give it a good try."

An Oxford University spokeswoman said: "Research using animals has, over the years, lead to treatments, vaccines and cures for diseases and conditions including polio, leukaemia, asthma and diabetes.

"While the University of Oxford respects the right of individuals to express their views peacefully, we are concerned that any individual might be putting their own health at risk in order to protest about the construction of a new building for lawful research which could help save lives in the future.

"When it is essential to use animals, we ensure that they experience the highest standards in animal welfare."