Following her urgent question in the Commons on horsemeat beef burgers, Shadow Environment Secretary Mary Creagh tweeted:
Heath hasn't answered why Horseburgers discovered by Irish authorities and not UK. How can he guarantee it won't happen again? Silence.
The horsemeat scandal demonstrates how long and complicated the food chain we all depend on is. Regulating our food supply is expensive.
Some of the best, and worst, jokes and gags from Twitter users discussing the discovery of horse DNA in some supermarket beef burgers.
We've seen the jokes on Twitter but the discovery of horse and pig DNA in beefburgers poses a serious question; where did it come from?