IT'S starting to feel like an episode of House of Cards.

US presidential candidate Ted Cruz has accused his Republican rival Donald Trump of trafficking in “sleaze” and “slime” as he denied sex scandal allegations levelled against him.

Cruz said the campaign has taken a "darker turn" and accused Trump and "his henchmen" for spreading untrue rumours that he cheated on his wife, Heidi.

"Trump demonstrated that when he's scared, when he's losing, his first and natural resort is to go to sleaze and to go to slime," Cruz said.

He added: "He's willing to attack anyone and everyone. And truth has nothing to do with it."

In response to Cruz's comments, Trump's spokeswoman Hope Hicks said: "There is absolutely no truth to this."

Trump also said in a statement that he knows nothing about the allegations about his rival, who he repeatedly calls “Lyin’ Ted”.

The angry spat followed a story tabloid National Enquirer ran on Friday quoting a ‘Washington insider’ as a source on “shocking claims” about five affairs Cruz supposedly had.

It followed a week in which Trump’s outrage over an advert featuring nude pictures of his wife descended into a bitter feud between the leading candidates for the Republican presidential nomination over their spouses.

The advert which triggered what some have dubbed ‘wife-gate’ came from an anti-Trump Super PAC and featured a risqué photo from a magazine shoot of the billionaire’s model wife Melania with the slogan “Your next first lady. Or, you could support Ted Cruz on Tuesday.”

In response Trump issued a cryptic tweet saying: “Be careful, Lyin’ Ted, or I will spill the beans on your wife!”

Cruz denied having any links to the advert, but Trump continued his attack by retweeting an unflattering picture of Cruz’s wife Heidi next to a photo of his wife Melania Trump, which had the accompanying message “No need to spill the beans. The images are worth a thousand words.”

It prompted a furious response from Cruz who told reporters: “I don’t get angry very often. But you mess with my wife, you mess with my kids, that’ll do it every time.”

He added: “Donald, you are a snivelling coward and leave Heidi the hell alone.”

On his Facebook page, Cruz has also accused Trump, who has not held a public event since Monday, of "hiding in Trump Tower" and campaigning by Twitter instead of holding events with voters.

Asked if he plans to vote for Trump if he becomes the party's nominee, Cruz said: "I don't make a habit of supporting people who attack my wife and my family."

In response to the allegations printed in the National Enquirer Cruz issued a statement calling the attacks “garbage”.

He added: “For Donald J Trump to enlist his friends at the National Enquirer and his political henchmen to do his bidding shows you that there is no low Donald won’t go.

“These smears are completely false, they’re offensive to Heidi and me, they’re offensive to our daughters, and they’re offensive to everyone Donald continues to personally attack.

“Donald Trump’s consistently disgraceful behaviour is beneath the office we are seeking and we are not going to follow.”

However Trump issued a statement saying he had no idea whether the National Enquirer story was true, but had “absolutely nothing to do with it” and did not know about it.

He added: “Likewise, I have nothing to do with the National Enquirer and unlike Lyin’ Ted Cruz I do not surround myself with political hacks and henchman and then pretend total innocence.

“Ted Cruz’s problem with the National Enquirer is his and his alone, and while they were right about O.J. Simpson, John Edwards, and many others, I certainly hope they are not right about Lyin’ Ted Cruz.”

One group hoping to capitalise on the ‘wife-gate’ will be the Democrats, with Trump - who has a history of making derogatory remarks about women - already deeply unpopular with female voters and Hilary Clinton aiming to become the first female president of the US.

A poll by NBC News/Wall Street Journal found 70 per cent of women voters have a negative view of Trump and almost half of Republican female primary voters said they could not imagine backing him.

Yesterday Trump tweeted: “The media is so after me on women. Wow, this is a tough business. Nobody has more respect for women than Donald Trump!”

How Twitter responded to Wifegate

@JohnFugelsang: Guys I don't care about #CruzSexScandal because it has no bearing on his ability to be an effective fascist psychopath

@Conservative_VW: I did not have sexual relations with those 5 women #CruzSexScandal

?@Jewyorican: And just when you thought the election couldn't get any more ridiculous, we get the Cuban Mistress Crisis. #CruzSexScandal

@TeaPartyCat: After #CruzSexScandal reveals Ted had 5 mistresses, Trump attempts to regain alpha male status by saying he has "10 mistresses right now!"

@kasthomas: Before we get too carried away with #CubanMistressCrisis (aka #CruzSexScandal) recall the National Enquirer has endorsed Trump for President.