robustness

As cases have cropped up in recent days - including those in Pennsylvania and a Chinese student being charged with illegally voting in Michigan - authorities have repeatedly pointed to their investigations as examples of the robustness of election safeguards.

"Tardigrades are fascinating animals and while they are famous for their robustness, it’s prudent to remember that they are extremotolerant, not extremophilic," Kolling said.

A letter from 2012 signed by Sir Vince to then-Labour leader Ed Miliband said he "remains fully confident about the robustness and integrity" of the Horizon software.

"But I do believe, given the emphatic nature of the replies, and the Post Office's use of court judgements as a proof point for the robustness of the system, at this stage in the process, I'm not sure it would have got any further."

She told the inquiry on Wednesday that the Post Office had initially reassured her about the robustness of the Horizon computer system and its chances of winning a case brought by 555 sub-postmasters five years ago.