Plans to stabilise cliffs after a series of rock falls have been branded irresponsible by a conservation group.

The Brighton Urban Wildlife Group said protected chalk cliffs behind the marina in the city would suffer irreparable damage if plans were approved.

Brighton and Hove City Council wants to spend £500,000 on the project, intended to stop a repeat of last winter's rock falls.

The popular Undercliff Walk where it passes the marina has been closed since a major rock fall in April.

The proposals include removing the top two metres of cliff, regrading the next five metres and using bolts and mesh to stabilise some other sections.

Phil Belden, of the wildlife group, said a full environmental impact assessment should be carried out before a planning application was considered.

He said the work would speed up erosion towards the main A259 and damage cliffs that provided a home to an internationally rare flower, the hoary stock.

He said: "It is irresponsible. It is basically council vandalism of a nationally important wildlife and geological site. They should take a measured view of the actual risk of all this."

The work would be limited to a short length of cliff, protected as a site of special scientific interest (SSSI), behind the Asda store.

The council has been told it would not be able to repeat the work on an adjoining section of cliffs at Black Rock because of their geological importance.

English Nature, the body responsible for policing SSSIs, has agreed to the work subject to the council agreeing a series of mitigation measures.

John Curson, of English Nature's Sussex office, said: "We regard this as a one-off because of its location. We don't expect to have more planning applications for similar work on the rest of the cliffs."

Councils were made responsible for the upkeep of protected sites such as SSSIs in tough new laws introduced earlier this year.

The council expects an application for planning permission to go before planners later this month, although it may be agreed by officers using delegated powers without going to committee.

A spokesman said it would be inappropriate to comment before the application was considered.