From the age of 8 to 13 I lived in Romford - a very "working class" area of outer east London, and I guess you would say I have a slightly cockney (or some might call it "estuary English") accent. I have a friend who is very cockney but she doesn't drop the gs at the end of words.
Commenting about the dropped gs is nothing to do with being snobbish or it being because Patel is a Conservative. I mentioned Sadiq Khan and he's Labour, and Beth Rigby is a political commentator, so nobody knows her political affiliations.
And, by the way, I don't recall any of the people who have accused some Gransnetters of snobbery complaining about this:
"At last week’s leadership launch, the BBC’s Laura Kuenssberg and then Sky’s Beth Rigby asked him [Johnson] about accusations that his campaign was a “chaotic mess” and then about his character. Johnson’s response was not to provide a riposte to the concerns among his former colleagues about whether he is “fit to be prime minister”; it was to laugh at Rigby’s accent."