Sea water quality at beaches in Brighton and Hove is among the worst in Sussex, according to a new report.

The Marine Conservation Society’s (MCS) Good Beach Guide 2011 revealed the city only has two recommended beaches – two fewer than last year.

Hove and Brighton Central dropped two grades from being recommended to being given just the basic level in the new guide.

Kemp Town was also awarded the basic level whilst Hove West and Saltdean beaches reached the MCS standard for excellent water quality.

In the rest of the county, South Lancing, Bexhill, Hastings and Camber were also ranked as basic – the minimum water quality set under European law before failure.

However, Sussex beaches improved overall with more recommended than last year.

The results come after West Street and Hove Lawns beaches in the city lost their Blue Flag ranking earlier this month under the system run by Keep Britain Tidy.

Brighton and Hove City Council’s environment cabinet member Pete West said the loss of recommendation for the beaches could harm the city’s image.

He said: “We will be talking with Southern Water to see what improvements can be made.

“It is obviously damaging to our reputation and local economy having these problems and we want that sorted but we don’t yet know the scope of what can be done.”

The MCS said there are many reasons for the drop in water quality but said they are “particularly concerned” about the level of dilute sewage flowing into coastal waters.

Water companies such as Southern Water are allowed to release valves called combined sewer overflows (CSOs), which act as emergency outlets for overloaded sewage systems after heavy rainfall.

Southern Water said heavy rain last summer has contributed to the high readings in some Sussex areas.

The company said the quality of bathing water can be affected “by factors outside” their control.

A Southern Water spokeswoman said: “The CSOs in Brighton rarely discharge. This is largely due to Southern Water’s stormwater storage tunnel under the seafront at Brighton and Hove. This stores stormwater during heavy rain.”