A Republican congressman has suggested that Donald Trump and Ted Cruz could settle their disagreements the old fashion way.

The Presidential rivals have been increasingly at odds over a number of issues, not least LGBT rights.

Trump branded Cruz a “liar” for running attack ads suggesting Trump supports equal marriage, while Trump has slurred Cruz as a “hypocrite” for taking money from gay donors while opposing LGBT rights.

Amid the pair’s squabbling, eccentric Iowa Republican Steve King – who previously offered to marry gay people to his lawnmower – made another strange suggestion in an MSNBC interview.

He said: “We don’t use that word [liar] where I come from, because when you make that kind of allegation, we look back at our founding fathers, for example, and realize that Aaron Burr and Alexander Hamilton fought a duel to the death over such allegations.”

He added: “Now we have them hurled out as though making that allegation somehow makes it true and makes it stick.

“I will say this: The things I heard Donald Trump say, you would never want a president of the United States speaking like that from the podium. Think of this press conference he just did.

“Think of the great seal of the United States of America in front of him. The president of the United States hurling those baseless accusations out, attacking people, attacking their character willy-nilly, calling them liars with no basis or substance.”

Elsewhere this week, Donald Trump declined to rule out a conspiracy theory that conservative Supreme Court justice Antonin Scalia was secretly murdered by liberals, after he died from a suspected heart attack.

Speaking to a right-wing radio host, Mr Trump appeared to pander to the host’s theory that Justice Scalia was murdered.

Mr Trump said: “I’m hearing it’s a big topic, the question… it’s a horrible topic.

“They say they found a pillow on his face. It’s a pretty unusual place to find a pillow.”

Murderers, of course, are renowned for leaving clues and murder weapons in places where they can be identified by right-wing conspiracy theorists.