LHR transit passengers?

“Should transit passengers using LHR pay APD tax?” Let’s debate.

According to the article below, the UK loses millions of £’s in lost revenue because a significant majority of passengers that use Heathrow use the airport as a transit hub to board onward connecting flights, and so they avoid paying the Air Passenger Duty tax (the tax that Mr Brown charges you just for leaving the country!)

…But every seat sold to a foreign transfer passenger costs the Exchequer up to £80 in lost revenue. If all their seats were occupied by people either starting their journeys at Heathrow or transferring from a domestic flight, the Exchequer would gain more than £500 million a year, it adds.

http://www.uk-airport-news.info/heathrow-airport-news-140508c.htm

I am somewhat divided on this issue…

If you think about it, as a transit passenger you should normally follow the ‘Flight Connections’ signs after disembarking from your inbound flight, and as long as your are connecting onto an onward flight within the same day, then you do not offically enter the UK, so on these occasions I dont think passengers should pay, however, if you are staying in the UK for a day or more and then getting an onward flight, then it seems right that they should be made to pay along with everyone else?

Does anyone agree?