The ex-Smiths frontman, who last month said the recent Norway massacre was not as damaging as the actions of the fast food industry, was playing the first of two shows in the capital when he questioned Cameron's response to the Tottenham riots.
"Does anyone think that David Cameron has been to Tottenham? I don't think so," the singer told the crowd.
Morrissey also revealed his pleasure at Prince Charles and Camilla Parker-Bowles's treatment at last December's student protests.
"In what our slanted media called the student riots, Charles and 'Camel' came face to face with the British public without the protection of Buckingham Palace or the police," he continued.
"And what happened to them, I couldn't stop laughing about for weeks - no, months."
> Morrissey defends Norway massacre comment
> Morrissey slams David Cameron in Glastonbury set
Listen to Morrissey talk about David Cameron and the royal family on Radio 4 earlier this year: