Jeremy Corbyn was paid to lecture civil servants
The Civil Service has paid Jeremy Corbyn more than £1,000 for him to lecture government officials.
David Cameron and foreign secretary Philip Hammond have said Labour under Corbyn poses a threat to national security.
But the body that trains civil servants decided government staff would benefit from his experience.
Records show Corbyn was being paid to give some of the lectures while he was campaigning to become Labour's leader.
Between May 2014 and July 2015 Corbyn gave nine lectures, three of them after nominations closed for the Labour leadership.
He was paid £1,350 by Civil Service Learning, the body that trains civil servants, over the period for lecturing.
Last month Hammond said Corbyn embarrassed and weakened Britain, and left foreign leaders "aghast".
It is understood Corbyn lectured staff on the workings of Parliament. Sources say other backbenchers have provided officials with similar guidance.
Corbyn, along with other MPs, is also credited with helping Civil Service Learning write a handbook called "Working with Ministers".
The Labour leader has never been a minister. Among its advice, the handbook reminds civil servants "ministers are human".
It also says officials must "retain the confidence of the Opposition, who must be sure that the Civil Service would serve them in government as assiduously as it is serving the present Government".
The Cabinet Office confirmed Corbyn had been hired to make presentations to civil servants.
A spokeswoman for the department said: "Long-serving MPs from all parties are often invited to speak to groups of civil servants about the workings of Parliament."