The two rivals collide Sunday night in the headline event at the O2 Arena, live on Sky Sports.

But Wardley has been merrily goading Clarke since he contentiously withdrew from a mandated purse bid last year.

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When his title shot was first ordered the big man from Burton was just six fights into his professional career. He's now still only eight in total, unprecedented for a British heavyweight title challenger. Clarke has only been the 10-round distance once and never the full championship 12.

Though the contest was eventually agreed, the intensity of their verbal clashes has only ramped up as they've drawn closer to fight night.

Wardley believes that is taking a toll on his opponent. "I think he's feeling the pressure of it all," he declared.

"He's even eluded to it a little bit," he continued. "I think he's used a lot of energy in the build-up to this fight, he used a lot of energy even in fight week."

Wardley, the champion, has had 16 pro bouts and all but one he's finished inside the distance.

He though has never been extended beyond seven rounds. Wardley also originally turned professional with no amateur experience baring a few unlicensed, 'white collar' bouts.

In contrast Clarke was vastly experienced as a GB boxer. He stayed on the programme in Sheffield for three Olympic cycles, which culminated in him winning a bronze medal at the Tokyo Games.

In Japan he was the captain of the most successful GB Olympic boxing team in a hundred years.

His years on the squad yielded plenty more accolades, including a Commonwealth Games gold medal, a European silver and very nearly a medal at the World Championships.

But if anything Wardley has used those credentials against him. He has cranked up the expectations for Clarke.

"Ultimately he's the Olympian, he's the one with a stellar amateur record, he's the one coming from that background," Wardley told Sky Sports.

"If little old white collar me beats him then, it leaves his career in a weird position.

"It's definitely a longer climb back and a longer road for a loss for him than it would be for me."

These barbs have a purpose. "I like to poke the bear and have a prod and see if I can get a reaction out of them," Wardley said.

"I like to give him a little poke and see him go off."

Keeping calm, the champion says, will make all the difference.

"It's key under the lights. Especially, big stage, big event, O2, high pressure, high pressure environment. There's a lot riding on the fight for the pair of us," Wardley said.

"Especially headlining a show, being the main one, is a different beast entirely."

Clarke shrugs that off. "I'd probably say I'm a bit emotional as well in the sense that I've got a short fuse. Which is sometimes good. Sometimes it's not so good. I'm just a normal, real person," he told Sky Sports.

"If you act like an idiot around me, you get told you're an idiot, it's that simple."

However he denies those emotions are getting the better of him. "Everyone talks about personal rivalry. I've got no rivalry with him," he said.

"I am treating it as another boxing match. I've had a 160 in my whole life, whatever it is, something like that, and what I will say is this is just another one.

"He's just a means to an end. There's no personal rivalry."

But there can be no doubt the competitive drive between the pair will be fierce. Wardley is convinced he has the edge, firstly in athleticism but nor is he overawed by Clarke's technical skills.

"Twelve rounds is no joke, especially at heavyweight, we're big boys we carry a bit of mass so it's not easy for us and a big question mark for him has always been stamina and getting through fights," Wardley said.

"He does the basics very well but maybe that's also a bit of a downfall. That he's so basic there's nothing too different," Wardley continued. "I'm not ignorant to think he's not a good fighter. He's a good fighter. But I think that is all he is.

"He's pretty well rounded, he puts some things together pretty well, aside from that there's no real attributes for me that really excel for him. He doesn't do anything particularly great, there's nothing I'm really extremely worried about.

"If I smell blood, I'm going to pounce on it," he warned. "If I hit you, you stay hit as well."

The risks for Clarke's career, if he does lose, are sizeable. But winning would grant him an instant place in sporting history.

Promoter Ben Shalom said: "He could become the fastest British heavyweight champion of all-time.

"This is everything that they've trained for their whole career. It's a huge British title fight," he continued.

"It's probably the biggest British heavyweight title fight since AJ-Dillian Whyte."

This bout is also a gateway to huge opportunity.

"The heavyweight that wins gets to go forward into a division that's moving very fast at the moment, there's a lot of money involved," Shalom said. "I think the winner has options and big options.

"Who's going to be doing those big nights, selling out those arenas and becoming a pay-per-view star.

"I do think it's one where for both of them that they'll look back on as the most important fight of their career, win or lose.

"I think it's got that much riding on it. I think their careers are going to take shape based on this."

Watch Wardley vs Clarke on Sunday night live on Sky Sports.