The town was put at the bottom of the league for the area with the cleanest streets in the East Midlands after 24.2 per cent of the streets were assessed as dirty.

The figures, which covered the 12-month period up to March 31, 2007 and were supplied by 40 councils in the area, were published as the Best Value Performance Indicator 2006/07 in the Audit Commission Local Government Compendium and ranked by the worker's union GMB from the cleanest to the dirtiest.

Towns are assessed on the amount of litter and waste, including dust, mud and glass fragments, found on public land and highways.

Judy Gregory, executive director of Daventry District Council (DDC), said the street cleaning methods used by the authority were currently being reviewed as part of steps to improve the service.

She said: "We acknowledge our performance figures for street cleaning are behind neighbouring districts, however we have seen a marked improvement over the past 12 months and we will continue to build on this.

"An audit of our environmental services last November showed an area for improvement is to ensure all neighbourhoods district-wide are maintained to an acceptable standard, but it also showed that most areas were cleaned regularly and to a good standard.

"We are re-examining our street cleaning methods and the frequency of our cleaning rounds to address the issues."

The council said that the 2007/08 figures, which it has supplied to the Audit Commission, show that the percentage of streets assessed as below an acceptable level in the district has fallen to 16 per cent.

Andy Worth, GMB regional secretary, said: "There are still too many councils which are not putting enough effort and resources into keeping its streets clean – and that has got to change. They need to employ more street cleaners."

DDC said ititiatives over the past year have included litter awareness events at Daventry market to advise shoppers on litter laws, deep cleans across the district, Operation Spring Clean – litterpicking sessions by community groups and parish councils – and creating a new role of education and enforcement officer work with local residents.

Elsewhere in the county, South Northamptonshire was joint third in the league table and Northampton came joint sixth.