Hundreds of women may have to travel up to 15 miles for routine breast screening, say organisers.

The Sussex Cancer Network had wanted to operate a mobile breast screening unit at the Tesco store in Lewes for five days a week.

However, store bosses say the car park is in too much demand on Thursdays and Fridays so screenings can only take place on Mondays to Wednesdays.

The store had originally refused to let the unit be based on the site but a compromise has now been reached.

The network needs to screen 4,000 women between May and July this year and can manage about 70 screenings a day.

It means some women will have to travel to Sussex House in Brighton if they have been given an appointment for a Thursday or Friday.

Screening co-ordinator Linda Garvican said: "The situation is not ideal. However, considering we weren't going to be able to use the site at all, three days are better than none.

"Some women will have to travel to Brighton. We are concerned that some women, especially those without their own car, will not go because it is too difficult to get there."

The National Breast Cancer Screening Programme has been running in East Sussex and Brighton and Hove since 1990.

It takes three years to screen all eligible women in the county so the programme is now on its fifth screening round.

Mobile units on community sites are used because the service wants to offer screenings close to where women live.

The programme pays for power to the site and its unit takes three or four car parking spaces. Women usually spend less than 15 minutes being screened.

A spokesman for Tesco said the company was committed to supporting the breast screening initiative and admired the work being done.

He said: "Unfortunately the car park is not large and there is a huge demand for spaces.

"We are particularly busy on Thursdays and Fridays and pressure on places is extremely high on these days.

"We want to do our bit to support the service and we believe this is the best compromise possible."