Speed limits have been defaced in a village on the edge of Oxford prompting authorities to slam the culprits as "irresponsible".

The 20mph signs in Cumnor were graffitied by an objector who changed the number to 40.

"Think for yourself" and "Cumnor Shills" were among the slogans endorsed by the vandal.

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Oxford Mail: '40' was added to the sign.'40' was added to the sign. (Image: Cumnor Parish Council.)

A Cumnor Parish Council spokesman said: "This irresponsible behaviour is endangering pedestrians, cyclists and drivers in the parish. 

"We’d rather the individuals responsible thought more about how to keep people safe rather than their need for speed.  

"The new 20mph limits in the parish were widely welcomed by residents, as was the 30mph limit for Cumnor Hill, something the parish council and residents campaigned for over many years following a string of accidents, including one that resulted in serious injury to a child."

Oxford Mail: They have been defaced.They have been defaced. (Image: Cumnor Parish Council.)

Oxfordshire County Council is rolling out 20mph speed limits as a replacement for 30mph areas "where there is local support" as part of its commitment to "safer roads".

The council cites research for its policies which suggests individuals are seven times more likely to survive if hit by a car driving at 20mph than if hit at 30mph.

The limits have proved unpopular with some residents who say they increase congestion and are unnecessary.

Oxford Mail: The limits have proved controversial.The limits have proved controversial. (Image: Cumnor Parish Council.)

A county council spokesman said: "Graffiti and vandalism are antisocial activities.

"By defacing speed signs aimed at making Cumnor safer by reducing the risk and impact of collisions, this person is making it more dangerous for people in this community.

"We will repair the damage caused and would urge anyone with information about these incidents to contact the police."