Guests of the hotel will be asked to add a voluntary £1 to their hotel bill during the two month period, which will then be given to specially chosen charities that help the homeless.
Money donated will help to provide a bed; a shower; a hot meal; medical help; training and employment; shoes for job interviews; starter packs for the newly housed; vans for food delivery; and support for the abused.
Last year the hotel raised a total of £2,473 for the campaign, an amount it hopes to surpass in 2012.
“At this time of year, it’s even more important for us to support those less fortunate than ourselves,” said Lancaster London general manager Stephen Kyjak-Lane.
“A £1 donation from each guest is such a small amount to give, but combined it can make a real difference to the lives of others.”