Three in four Republicans believe that Joe Biden did not legitimately win the November 2020 presidential election, a new poll has found.

GOP supporters' lack of confidence in the election results has been fueled by Donald Trump and Republican lawmakers continuously pushing unfounded claims of voter fraud.

Judges across the U.S. have been throwing out swathes of legal suits filed by Trump's team in a bid to overthrow the results, saying there is not sufficient evidence to indicate widespread election fraud. However, Trump supporters continue to peddle the claims, leading to an angry mob storming Capitol Hill on January 6.

Self-identified Republicans are now less likely to have confidence in American elections than Democrats, according to new data.

A Trump supporter holds a sign that reads "Stop the Steal" outside Trump National Golf Club on December 13, 2020 in Sterling, Virginia. Only 19 percent of Republicans believe Joe Biden legitimately won the election, according to a new poll.Getty Images

A CNN poll, released on Sunday and conducted by SSRS between January 9 and 14, shows that 75 percent of Republicans do not think that Biden won the election legitimately, compared to 1 percent of Democrats and 36 percent of independents.

With 6 percent of GOP supporters saying they are unsure, this leaves just 19 percent who do believe Biden won legitimately, compared to 99 percent of Democrats and 66 percent of independents.

The proportion of Republicans who said they have little or no confidence that elections in America today reflect the will of the people also stands at 75 percent, including a majority (57 percent) who say they are not at all confident in U.S. election results, according to the data.

Meanwhile, more than half (58 percent) of Republicans think there is solid evidence to support the fact that Biden did not win legitimately while 13 percent said they only have a suspicion

It comes as opinions of the GOP and Trump have dropped as the president prepares to leave office with the lowest approval rating in the whole of his four years in the White House, CNN reported.

The broadcaster's research also found that Republicans are split on the issue of whether the party should move on from Trump with 48 percent saying the party should leave him behind while 47 percent said it should continue to treat him as their leader.

It comes after the FBI has warned of the potential for more violent pro-Trump insurrection on Wednesday when Biden is sworn into office.

Army Secretary Ryan McCarthy has warned National Guard commanders to be on the lookout for any potential inside threats from service members assigned to security operations for the Biden's inauguration.

Concerns about a possible inside attack among defense officials has prompted the FBI to screen tens of thousands of National Guard troops sent to Washington D.C. to help secure Biden's inauguration, according to the Associated Press.

Meanwhile, Trump will not be attending Biden's inauguration and is reportedly planning to leave the White House a few hours before the President-Elect is signed in.

Officials are planning a farewell ceremony for the outgoing president at Joint Base Andrews in Maryland before he heads to Florida aboard Air Force One.