Andrew Palmer (52) was sentenced to 20 months in jail after twice breaching a sexual offences prevention order and a community order.
Palmer, who was an Labour electoral agent for Peterborough City Council nominees, had twice spent time behind bars for possessing rape images of children.
The second offence took place in 2007 and earned him eight months in prison.
Palmer had been the agent in the 2012 council elections for Labour group leader Nazim Khan as well as Jo Johnson and John Richard Knowles.
He added: “The local constabulary have significant concerns about him.”
The sexual offences prevention order he had breached was handed out in October 2014, for breaching a previous order, and prevented him from spending unsupervised contact with children.
The first breach occurred on December 29 when he paid an unexpected visit to a house where a young child lived.
The second breach was on February 2, 2015 when police arrested him and he admitted to having deleted messages from a phone messaging application called WhatsApp.
It was thought the content may have been sexually explicit.
He had pleaded guilty to the charges on February 10 and was sentenced on the 18th at Peterborough Crown Court.
Sentencing Palmer, Judge Peter Murphy said: “It seems clear to me that you were aware from the end of October that not only you were barred from certain activity on the internet, but not to have unsupervised contact with young children without informing a parent or guardian of previous convictions.
“You turned up under cover of working with a housing association. You had several phones with you and the implication was clear.
“On the second count, there is not much information on what was deleted on your phone.
“But a previous matter indicated you have a clear interest in paedophilia and and the pornographic images of young children.”
Describing Palmer as a danger to the public, Judge Murphy added: “It’s quite clear your offences were a calculated defiance of court orders.”
Palmer received eight months in prison for both of the two breaches of the sexual offenses prevention order which will run consecutively.
In total, Palmer had seven previous convictions for 13 offences, the first of which was for indecent assault in 1979.
The mother involved in the court case said: “I wish he had got longer. I was shocked. We knew nothing.”
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