Opposing sides in the row over Oxford University's new £20m animal research laboratory have both staged protests.
Supporters of animal experiments are marching in Oxford
Supporters of the new Oxford Biomedical Research Facility held a rally in favour in central Oxford on Saturday.
Meanwhile, anti-vivisection campaigners demonstrated in Moreton-in-Marsh, Gloucestershire, outside lodgings of contractors working on the building.
Mel Broughton, from SPEAK, said they were not putting the workers at risk, by identifying their accommodation.
He said: "This is a place where millions of animals are being experimented on.
"They're going to suffer and they're going to die and we feel we absolutely have a legitimate right to protest within the law against anyone who's involved in it.
"That's exactly what this protest is about."
Activists were protesting outside lab contractors' lodgings
Tom Holder, from Pro Test, which organised the march in support of medical testing on animals, said: "We've seen that the anti-vivisectionists have managed to close down labs in Huntingdon, they've managed to delay work on the labs in Cambridge, in Oxford for fourteen months; so there is still a lot to be done.
"Plus we're going on the wider view this time of actually trying to change public opinion rather than simply sneakily get a lab built."
Last week, Oxford University was granted an extension to its injunction against animal rights activists.
The High Court widened an order to protect staff, students and contractors from harassment by some protesters.
Construction of the laboratory in South Parks Road was halted in July 2004 when contractors pulled out after a campaign led by Speak.
Oxford University said since work on the centre resumed in November last year, threats and criminal damage had increased.