The incidents took place between 11 September 2023 and 12 May 2024.
Brandt, a former councillor, was arrested in March 2024 and given a conditional caution the following month, requiring him not to contact Dame Penny, but he then left two voicemail messages for her.
The court heard in one of the messages, he said: “I am going to go on gently knocking at your door in order to shake your hand, I am not giving up.”
Explaining why he wanted to meet Dame Penny, the former elected member of East Hampshire District Council said he wanted to commiserate with her over her failed leadership bid.
He added: “I wanted to congratulate her because she was a reforming leader of the Commons, I wanted to congratulate her on the coronation, chat to her about her time in office, have her sign a copy of her book.
“It was entirely political and entirely harmless.”
Dame Penny said in a statement to police that she “feared sexual violence” because of Brandt’s “creepy” behaviour.
Passing sentence, Judge William Mousley KC told him his actions had a “significant and enduring” impact on Dame Penny.
“As an MP, [Dame Penny] was vulnerable as she would make herself available to meet members of the public,” the judge said.
“There have been before and since incidents where MPs have been attacked or worse in the course of carrying out their jobs as constituency MPs, and Penny Mordaunt would have been only too aware of that and would justifiably been frightened of incidents occurring in her constituency.”
Brandt was sentenced to 12 weeks in prison for the stalking offence and eight weeks to serve consecutively for the breaches of the stalking protection order.
