Charles announced in February he had been diagnosed with cancer, aftertreatment for an enlarged prostate, and the following month the Princess of Wales revealed she was under going a course of chemotherapy, since completed, and she has made a partial return to public duties.

The king's ongoing treatment is understood to be heading in a positive direction, and after initially postponing all public-facing engagements here turned to events in April, carried out a major southern hemisphere tour in October and his diary in the run-up to Christmas appears very similar to his pre-cancer period.

Fitzrovia Chapel, designed by the architect John Loughborough Pearson with work beginning in 1891, is a few minutes' walk from Oxford Street, Europe's busiest shopping destination, but offers a tranquil space and is a popular wedding venue and arts exhibition site.

It was used by patients, medical staff and the public visiting the Middlesex hospital, which closed in 2006 and had stood on the site since 1755 before being demolished in 2008.

Following the broadcast, the Christmas tree, a living specimen covered with sustainable decorations, was donated to Croydon BME (Black and Minority Ethnic) Forum and Macmillan Cancer Support's Can You C Me? project, which strives to tackle ethnic inequalities in cancer care.

It will be placed in the Royal Trinity Hospice in Clapham, south London, which has the queen as its patron.