A mild winter and a cull of urban foxes are being blamed for an increase in the number of rats spotted in Barnet in the past year.

Barnet Council says in the latest financial year it has received 530 reports from members of the public of sightings of rats in the borough's streets, up from 367 reports in the year 2005-6.

The number of complaints about rats inside buildings also went up, from 39 to 52, over the same two periods.

Clive Cohen, Barnet's representative at London Wildlife Trust, said: "There are a number of things that affect rat populations. If refuse is not collected regularly, rats will thrive, and there are areas in the borough where refuse is more pronounced than in others. Cleansing sewers regularly is also important.

"Another issue is foxes. In some areas in Barnet, the number of foxes has been reduced too much, and foxes control rats. At this time of year rats move away from their wintering quarters to breeding areas, which are frequently away from houses."

A council spokesman said more rats may have survived because of the mild winter.

Barnet Labour group's environment spokeswoman, Councillor Kathy McGuirk, had a different explanation: "It's no surprise that rat infestations are up.

"The Tories cut the pest control service in 2004, but were forced to re-introduce it after a deluge of complaints and a petition signed by 3,300 residents.

"The fact that they increased the charges to £108 has meant take-up of the service has reduced significantly. In 2003 the council's rat-catchers made about 6,000 visits compared to only 500 in the four-month period after the charges were introduced."

Councillor Melvin Cohen, the council's cabinet member for planning and environmental protection, had a third theory: "In 2006 we introduced a comprehensive pest control service, therefore more people have contacted the council to get vermin cleared."

The council's pest control team can be contacted on 020 8359 7997.