倫敦地鐵聖誕日是否停駛 ??

Yes there will be no transport on 25 and 26 december.
Try to get a hotel on 24 December and then you can travel on a shuttle bus from the hotel. Bus fare around £5 pp.
You can also check if there is any Airport bus on Christmas Day on your arrival in UK at the Information Desk. The bus will go round the city centre in London.
There are lots of hotels near Heathrow, e.g. Holiday Inn, Holiday Inn express, Crown, Novotel, Hilton.
For holiday inn, the price will be about £79 per room/night, inl. breakfast.
Even myself have to change my holiday to January though the price of air ticket is cheap on Christmas Day!

地鐵絕對唔會停駛的. 請放心! London Tube 差唔多係倫敦人既命脈黎 ka la. 點會停? 至於你話你會 12月24 (到) / 25日 (離開). 建議你租住 Heathrow 附近既酒店 lor. 唔好出市區喇. 因為所有野都 close 晒 ka. shopping 個 D 唔使 lum. 而且搭 airport express train 出入都好貴 ka. 差唔多要 HK$250 一程. 咁倒不如住係機場附近 D 細 hotel ba la.

至於如果你迫不得已要由市區搭的士往 Heathrow 的話. 費用約 $45 磅. 因我上次去搭過.