"Falsely stating that a product will only be available for
a very limited time, or that it will only be available on
particular terms for a very limited time, in order to elicit an
immediate decision and deprive consumers of sufficient
opportunity or time to make an informed choice."
Here's another one:-
"A trader falsely tells a consumer that prices for new houses
will be increased in 7 days time, in order to pressurise him
into making an immediate decision to buy."
From the Office Of Fair Trading UK:-
I see so many marketers saying the price will go up tomorrow if you don't buy now! Is this breaking the law?