Nearly all the political parties seem to think they can cheat the system. When Nigel Farage stood in Thanet comes to mind, when it was reported that the Tories bused in lots of supporters to canvass and paid their hotel bills, which would surely have put them over the election spending limit.
I used to be Treasurer of a local UKIP branch and had to account for every single expense, and righty so. We were always way under the limit threshold though as we only had a couple of grand in the bank, whereas the bigger parties were spending in the tens of thousands at election time.
Then, of course, there was Cameron's £9 million Remain leaflet sent out to every home which, conveniently, was posted before the official election expenditure period started!!