You have to look carefully at today's cartoon by Mac from the Daily Mail to 'get' the joke. Do you? (Click on the image to enlarge.)
A couple are working in their garden. The husband is mowing the lawn (or cutting the grass) with a lawnmower, and his wife is trimming the hedge with a pair of shears. Suddenly, the house next door collapses and disappears into the ground. The woman comments, "Cameron must be getting desperate. Is he going to do that to all Brexit supporters?"
The people in the collapsed house are in favour of Brexit (i.e., Britain leaving the EU). David Cameron is the UK prime minister, who wants Britain to remain in the EU. The woman imagines that Cameron has somehow caused the house to collapse to reduce the Brexit vote in the upcoming EU referendum, which takes place on 23rd June.
At first, I thought the cartoon was connected to a story about a house that collapsed in North London as a result of a botched basement extension, but then I looked more closely and saw the sign "UK Fracking Co." in the background. In fact, the cartoon relates to the landmark planning decision in Yorkshire, which has opened the way for drilling projects across Britain. Many people are opposed to fracking because they claim it poses a threat to the countryside. In fact, fracking was suspended in Britain in 2011 after a drilling operation in Lancashire was blamed for causing two small earthquakes. You can read more about the issue here.
Note the use of the modal verb 'must' to indicate that one is sure something is true, even is it's not proven. He must live near here because he comes to work on foot. We don’t know where he lives but we’re sure it’s not far away. See here for more on this grammar point.