It’s weird that the American usage of “sleaze” seems like it is primarily directed at the news media itself for content that is excessively prurient or smearing or untruthful, or perhaps “corrupt”.
Is the relationship there still in the British usage? Are they saying, “We are accusing the PM of ‘sleaze’, which is to say, please disregard this, because it isn’t really even worth mentioning and a despicable character assassination attempt on our part, that we are only forced to print because it unfortunately happens to be the truth”?