British police have apologised for failing to help a mother who killed herself and her disabled daughter by setting fire to their car after years of abuse from a gang of youths.

Fiona Pilkington pleaded for police assistance as she and her family suffered 10 years of torment and violence at the hands of the gang in Bullwell in central England, an inquest into their deaths heard.

But their requests to officers and local authorities were not given priority and their bodies were found in their burning car near their home in October 2007, the court heard.

A jury at the inquest concluded on Monday that police failure to help the family properly - despite 33 calls logged to police over the 10 years - contributed to Pilkington's decision to end their lives.

"Calls were not linked or prioritised," the jury foreman said.