Plans by Cambridge University to build a controversial laboratory which will test on monkeys have been criticised at a public inquiry.

The British Union Against Vivisection (BUAV) told a planning inspector the development was unnecessary and would be likely to attract a large number of protesters.

The university has already twice been refused planning permission for the neuroscience laboratory, which it says would carry out crucial research into diseases such as Alzheimer's and Parkinson's.

The planning inspector will now make recommendations to Deputy Prime Minister John Prescott, who is due to announce his decision later this year.

Local politicians had concerns about protests

The university wants to build the laboratory on green belt land on Huntingdon Road, to the north of the city.

South Cambridgeshire District Council opposed the planning application last year following police fears about public safety.

The decision was criticised by Prime Minister Tony Blair, who said it blocked progress in medical research.

He said anti-vivisectionists - who have already held several demonstrations at the site - must not be allowed to hinder scientists.

BUAV Chief Executive Michelle Threw told the inquiry: "There is a deep suspicion about the regulation of animal experimentation."

She also claimed the university had refused to discuss the proposals, resulting in "the suspicion that there is something to hide".

Building work will only be permitted on the green belt land if it is deemed to be in the "national interest".

Earlier on Wednesday, Cambridgeshire Police was given an extra �1.1m Home Office grant to help with the costs of policing animal rights demonstrations.