The Government has been dealing with the fallout of Sroubek being granted residency in September last year, despite being in jail for drug-smuggling.
After Immigration Minister Iain Lees-Galloway ordered a review of the case, a new deportation notice was issued to Sroubek based on previous convictions in the Czech Republic.
Sroubek has appealed. The Immigration and Protection Tribunal is yet to set a date to hear the appeal.
In his letter to Jacinda Ardern, Karel Sroubek snr said that he was "frustrated beyond belief" that his son had been subjected to "the gross abuse of political power" by National MPs.
He suggested that National was behind his son's case appearing in the media shortly after Sroubek placed a caveat on a $2.3 million Remuera property that the estranged wife had put up for sale.
"Immediately after filing [the] caveat in October 2018, his wife with her new partner and his political friends have unleashed unprecedented, frantic and mendacious persecution of my son," Sroubek snr said in the letter.
The estranged wife is reportedly dating Mark Davey, a former Waitemata Local Board member who ran on the centre-right Auckland Future ticket in 2016.
Sroubek snr said that the estranged wife's concerns for her safety only surfaced after Sroubek placed a caveat on the property.
"If she was really worried about safety, as she now claims, why did [she] not ask for protection immediately after the alleged threat on May 3, 2018 [from a phone call with Sroubek]?
"Why did she only start to worry about her situation in November 2018 immediately after the filing of the caveat upon their matrimonial house? The real reason is quite obvious – to totally discredit my son via political friends who portray him as a gangster and demand his deportation."
Steele said the estranged wife raised safety concerns in May.
"Our involvement with protection matters has been paramount and under way since May 2018. The caveat was not placed on our client's parents' property until October that year. The two matters are separate.
"Our client's fears for her safety remain."
In his letter, Sroubek snr also asked Ardern for his son to be treated well in prison and said that his son, a low-risk prisoner, had been put in a cell block with high risk prisoners, including a convicted murderer.
"I have serious concerns about any life for my son here in the Czech Republic but I also now have serious concerns about his health and life in his current situation in New Zealand."
Sroubek is being held at Wiri Prison in South Auckland, which is operated by Serco.
A spokesperson for Serco said Sroubek was moved from a self-care residence unit to another area as punishment for taking part in an unauthorised phone call.
Sroubek snr said the publicity around the case had made it even more dangerous for his son to return to the Czech Republic.
"All I am asking for is that you provide a fair and equal opportunity for my son – a position guided by fairness above politics."
He called National's justice spokesman Mark Mitchell "unprincipled and opportunistic" for speaking out for the estranged wife.
Mitchell said it was "incredibly disappointing" to see attacks on Sroubek's estranged wife.
"Mr Sroubek's ex-wife is a victim who should be being protected, but instead has been exposed to vitriol and character assassination by Winston Peters and the Sroubek family – all because this Government made the bad decision to let a convicted criminal and gang associate stay in New Zealand."
A spokesperson for Ardern said the letter had been received.
"The Government has decided to deport Karel Sroubek. Ministers did not have all the critical information when making the first decision, but now that we have all the info, he is being deported," the spokesperson said.
