A live debate between the two candidates vying to succeed Boris Johnson as British Prime Minister came to a dramatic end on Tuesday when the moderator of the debate fainted, Reuters reports.

Foreign Secretary Liz Truss and former finance minister Rishi Sunak had been sparring over their plans for about 30 minutes when there was a loud crash in the studio.

It occurred while the camera was on Truss in the debate hosted by Talk TV and the Sun newspaper. Truss held her hands to her face and said, "Oh my God", and the broadcast was then cut.

Talk TV said the presenter, Kate McCann, had fainted.

"Although she is fine, the medical advice was that we shouldn't continue with the debate. We apologize to our viewers and listeners," Talk TV said on Twitter.

Both Truss and Sunak later sent messages on Twitter wishing McCann well.

Last week, Britain’s Conservative Party chose Sunak and Truss as the two finalists in the election to replace Johnson.

Sunak and Truss came first and second respectively in a secret vote by Conservative lawmakers. Trade Minister Penny Mordaunt came in third and was eliminated.

The winner of the party leadership vote will be announced on September 5 and will automatically become Britain's next prime minister.

Johnson announced earlier this month that he will resign as Conservative party leader amid resignations by several of his ministers.