I don't read The Guardian unless I'm looking for fake news.
One method seems to be cruel in error and the other cruel in principle. At least with stunning - even if it doesn't work every time - an attempt is made to lessen suffering.
Muslims when they do stun do not use the more effective captive bolt method of stunning. They are not "almost identical" methods of stunning as Jon59 suggests. Many animals need to be given the electric shock method of stunning more than once. It is stressful and unnecessary. Jon59's line of argument is a red herring. He is trying to divert the argument away from the increased use of a cruel method of killing animals in the Uk to whether I am an Islamaphobe.
Another thing that is overlooked is that Muslims are only allowed to use religious slaughter for consumption by Muslims. They are deliberately overproducing halal meat.
https://www.gov.uk/guidance/halal-and-kosher-slaughter