The furore over Donald Trump listing Mitt Romney as a potential pick for US Secretary of State has intensified with one top aide calling reporting of her opposition to his selection “sexist”.

Kellyanne Conway, who serves as one of Mr Trump’s top strategists, was pushing back against news reports that she had angered him by publicly airing doubts about Mr Romney last week and over the weekend. She claimed on MSNBC that her position in the team was secure.

Earlier, MSNBC had reported that other top aides to Mr Trump had been “baffled” by how strenuously Ms Conway had been undermining Mr Romney, who was the 2012 Republican nominee and before that the Republican Governor of Massachusetts.

The background sniping can be of little help to Mr Trump. There are few cabinet positions more critical than Secretary of State and his final decision is now keenly awaited. Mr Trump is expected to meet with Mr Romney for a second time since his election victory on Tuesday.

President-elect Trump has now returned to New York from his Thanksgiving weekend sojourn in Palm Beach, Florida. Ms Conway is still at his side and is still widely seen as one of the most pivotal figures in the transition team having guided Mr Trump to victory in November. Her aggressive response to a possible Romney pick has thus been all the more surprising.

She has justified it in part by pointing to the admittedly extremely harsh attacks that Mr Romney launched against Mr Trump during the campaign, notably when there was a still a chance that he might not become the Republican nominee. But nominating him for Secretary of State would offer some pluses for Mr Trump: it would be seen as an olive branch to the Republican mainstream and his nomination would be quickly confirmed by the Senate.

Ms Conway made her views known again in TV interviews on Sunday. “I'm all for party unity, but I'm not sure we have to pay for that with the secretary of State position,“ she said on CNN's State of the Union.

“I'm just saying, we don't even know if Mitt Romney voted for Donald Trump,” she went on. “I think there are concerns that those of us that are loyal have, and we want a secretary of State who's loyal to the president.”

She wondered out loud why Mr Trump even imagined Mr Romney would be qualified for the job of America’s top diplomat. That appeared to ignore the fact that he has already selected a series of people for cabinet jobs with scant-to-zero qualifications for the duties they are meant to take on, including Governor Nikki Haley, slated to be the next US envoy to the United Nations.

Trump and Romney after their first meeting in Bedminster, New Jersey, earier this month (Getty)

“Governor Romney, in the last four years, has he been around the globe doing something on behalf of the United States of which we're unaware?“ Ms Conway asked tartly.

She has not been alone, however, it trying to throw sand in any cogs that may be turning for Mr Romney. On Monday, Congressman Chris Collins, who was the first Republican in the House of Representatives to support Mr Trump during the campaign, blasted the idea of his being Secretary of State.

“What do I know about Mitt Romney? I know that he's a self-serving egomaniac who puts himself first, who has a chip on his shoulder, and thinks that he should be president of the United States,” Mr Collins told CNN. “There's no love lost between me and Mitt Romney,” he added.

Other contenders for the job that Ms Clinton once held include Rudy Giuliani. However, the former Mayor of New York could face possible ethical problems because of private consultation work he has done for foreign governments and leaders in the years he has been out of public service.