Security has twice been breached at Brighton's Royal Pavilion

The GMB union's demand - in a letter to Brighton and Hove City Council's chief executive - follows two separate thefts of high-value artefacts recently.

It said there was "grave concern" over "ongoing staff cuts" at the pavilion.

The council said it was "working positively" with the union at a local level, and a meeting to review staffing issues was planned for 13 September.

'Ludicrous situation'

The first theft, on 4 June, saw a silver serving dish go missing from a public display area of the pavilion.

On 17 August a security guard found that three pieces of art nouveau jewellery had disappeared from a locked drawer.

The council has said it is assessing "all aspects of security", including the buildings and CCTV, collections, staff and visitors.

The pavilion is run under the city council's museums service

It said local union negotiations were at an early stage.

"Our priority has to be the continued improvement of the security, visitor experience and the value and efficiency of the city's heritage facilities and collections," a statement said.

"We will continue to work positively with the GMB to achieve this."

The union, which represents security workers at the Royal Pavilion, claimed a "ludicrous situation" had seen staffing levels cut from 57 in the mid-1980s to 26 now.

Spokesman Paul Maloney led calls for five new full-time workers at the site.

The Royal Pavilion grew out of a farmhouse in the late 18th and early 19th centuries, and was extended into a seaside residence for King George IV.

The Indian-style palace and other buildings are fitted with many Chinese decorations and adornments.