To clear up ummmmm's answer, there is indeed such a thing as common law and is is an important part of the English legal system. But there is no such thing as a common law marriage.
I couldn't see anything in the Queen's Speech about the legislation, but it could still be introduced and it would be nowhere near the weirdest thing the government has done. The problem will be sorting out the difference between a casual relationship and a serious one. As ummmm says, the solution is quite simple for anyone who does not mind being committed.