No shit, encourage the citizens to have less kids, so we can move more in.
http://www.express.co.uk/news/uk/752175/BBC-star-Chris-Packham-says-Britons-should-STOP-having-children-amid-immigration-surge
https://www.theguardian.com/society/2014/oct/28/how-save-planet-stop-having-children-doctors