The siblings of a Republican congressman aiming to hold on to his seat in the US midterms have appeared in campaign videos backing his Democratic rival.

Paul Gosar - a loyal defender of President Donald Trump - is facing a challenge from David Brill in Arizona ahead of the upcoming elections in November.

The conservative politician is a controversial figure, having made negative comments about Senator John McCain and spoken out in defence of English Defence League founder Tommy Robinson.

Image: Republican Paul Gosar has been effectively disowned by his siblings

He has also promoted a conspiracy theory that the violent march of neo-Nazis in Charlottesville last year was a left-wing plot to stoke racial discord and undermine the president.

Siblings Tim, Jennifer, Gaston, Joan, Grace and David have long been estranged from their brother, and have now formally declared their opposition to his re-election campaign and support for Mr Brill.


Image: Mr Gosar said the Charlottesville march - featuring members of the Ku Klux Klan - was a left-wing plot

In a series of campaign videos posted online ahead of their broadcast on US television, each of them give their view on why their brother is an unsuitable representative for Arizona and deserves to lose his seat.

Grace accuses her brother of "not doing anything to help rural America" and advises voters who "care about healthcare and their children's healthcare" to "hold him to account".

Mr Gosar has been a vocal critic of the American Health Care Act (better known as Obamacare), describing it as "an unmitigated disaster" that had failed Americans with "spectacular ineptitude".

In another video, Grace says: "It would be difficult to see my brother as anything but a racist."

Joan accuses Mr Gosar of "trading a lot of the values we had at the kitchen table" to further his career, and David said his siblings felt the need to "stand up for our good name".

And in another clip, Jennifer criticises his stance on refugees and immigration, including his use of the term "illegal aliens", and accuses him of lacking integrity.

The Phoenix New Times reports that the David Brill campaign team made contact with the Gosars after seeing Twitter posts from David harshly criticising his brother.

In a previous interview with the newspaper at the time of the Charlottesville clashes, David described the congressman as "an embarrassment to the family".

Several of of the siblings have reportedly made financial contributions to the campaign to oust their brother, who was re-elected with 71% of the vote in 2016.

Sky News has contacted Mr Gosar's office for comment.