The first promotional clip for Barnaby Joyce and Vikki Campion’s tell-all with Seven’s Sunday Night show suggests pressure was put on the couple not to have their son Sebastian.

A dramatic voiceover for the promo – accompanied by a graphic of newspaper headlines flashing across the screen – intones viewers will find out about “people who tried to stop this baby being born”.

“Political pressure, they said, if they, if you don’t, they are going to come after you,” an emotional Ms Campion says on camera.

Then she and Mr Joyce say simultaneously, “They did.”

Meanwhile, a music backing track sounds like the sort that is played when a moustache-twirling baddie is about to step from the shadows and bump someone off in a 1940s melodrama.

Whatever the truth of exactly what the pair is discussing, Sunday Night has managed to give an extra veneer of salaciousness to a love story already bedevilled by controversy.

She’s at the centre of the biggest political sex scandal in decades, yet nobody has heard her side of the story until now. On @sundaynighton7, Vikki Campion speaks to @alextcullen for the first time about her illicit affair with @Barnaby_Joyce. #SN7 – June 3 – 8.30pm @Channel7. pic.twitter.com/LkXu6GazKE

— 7NEWS Spotlight (@7NewsSpotlight) May 30, 2018

Ms Campion is Mr Joyce’s former media adviser, and the couple’s romance after the end of his 24-year marriage and the revelation they were expecting a child led to the then deputy prime minister stepping down from his job in February.

Sebastian was born in April, making Mr Joyce, who has four daughters with wife Natalie, a five-time father at age 51.

In Sunday Night’s words, it was “the illicit love affair that rocked Australia”.

But Ms Campion, who is seen holding Sebastian’s little hands while bathing him, says “everything was worth it” for her son.

Still, she breaks down and is hugged by Mr Joyce on camera. As Sunday Night puts it, “Now, Vikki Campion comes clean.”

Stumbling over her words, the new mother explains herself: “You can’t help, I couldn’t help it, I, you can’t help who you fall in love with.”

Immediately after – in an outburst that may end up being totally unrelated to Ms Campion’s sentiments – Mr Joyce shudders as he says, “I’ve failed, I’ve failed, I’ve failed, I’ve failed, I’ve failed.”

According to the show, nothing is “off limits” in the interview, and viewers will “meet the little baby at the centre of it all”.

Seven secured the interview with Mr Joyce and Ms Campion for a reported $150,000, a deal he was forced to defend on Tuesday.

The backbencher said it was his partner who decided to accept the six-figure payment, telling The Australian, “If it was just an interview with me as a politician, I am not going to charge for that.”

But he said the show wanted to “get Vikki’s side of the story” and that “drones and everything over my house” made him feel that, “If everybody else is making money then [I am] going to make money out of it.”

It was then reported that Mr Joyce had been granted extended leave and wouldn’t be returning to parliament until August.

But he said in a Tweet on Wednesday afternoon that reports of the length of his leave were incorrect.

Contrary to reports, I’m taking leave until June 15 following a routine check up. The medical certificate provided allowed for a month. 1/2

— Barnaby Joyce (@Barnaby_Joyce) May 30, 2018

A Melbourne corporate PR specialist told The New Daily the pair’s actions in selling their family story flies in the face of what he advises clients.

“My strategy is unless there’s a compelling reason, do nothing,” said the expert, who counts high-profile athletes and business heads as clients.

“I don’t know how this adds to relieving their grief and stress. I do get the intrusion of paparazzi, I’ve seen it with a lot of my clients, but if this was a means of trying to manage media intrusion, they’ve made a bad judgement.”

Saying he is concerned Mr Joyce “is a bloke who doesn’t look well,” the expert had one more tip for the new dad.

“Barnaby would do well not to throw his partner under the bus again. It’s a flawed strategy.”