Sarah Palin has accused her critics of “a blood libel” in their coverage of her controversial statements last year, about a Jewish congresswoman who was shot and severely injured in Tucson on Saturday.

Speaking in an online video broadcast, Mrs Palin said: "Especially within hours of a tragedy unfolding, journalists and pundits should not manufacture a blood libel that serves only to incite the very hatred and violence that they purport to condemn.

“That is reprehensible.”

The term usually refers to the medieval blood libel, in which Jews were accused of killing Christians to use their blood for religious rituals at festivals. One example of this occurred in 1255 in the British city of Lincoln, when 18 Jews were hanged after being falsely accused of the murder of a local boy.

The Tea Party leader and former vice-presidential candidate has been the subject of a furious media debate over the power of rhetoric in the four days since Gabrielle Giffords was wounded and six other people killed at a political event.

Pundits have condemned her use of a map showing cross hairs from a gun over the constituencies of Democratic Party candidates, including Ms Giffords, subtitled "Help us prescribe the solution".

Others have noted a remark on Twitter calling on opponents of healthcare reform not to retreat but instead to “reload”.

After the map first appeared Ms Giffords, the first Jewish politician of any party to represent Arizona in Congress, told news channel MSNBC:

"When people do that, they've got to realize there [are] consequences to that action."