It’s not quite Christmas without a huge decorated spruce - and the one outside Parliament is one of the most iconic.
This year, the tree is more than 40 feet tall, and stands proudly in New Palace Yard, near the Elizabeth Tower and Big Ben.
The tree is an annual tradition at the Houses of Parliament - but here are seven festive facts you probably didn’t know about the yuletide staple.
They range from the number of people needed to put the massive tree up and where it's selected from.
1. How many people does it take to put up a Christmas tree?
Five to six workers and a crane, actually.
Last year, Terry Cole and Geoff Bullock from Parliament’s In-House Services and Estates Team celebrated putting up the well-photographed tree for the 25th time.
One year the tree blew even down but the duo managed to arrange a crane on the same day and it was up and lit by the next morning.
Another year it had been snowing and they found a frozen pheasant stuck in the branches that had travelled with the tree to Parliament.
2. It's specially selected
This year’s tree, a Sitka Spruce, was selected from more than 155 million trees in the 600-hectare Kielder Forest in Northumberland.
The tree is picked out by experts so it looks good from every angle, before being felled by an experienced chainsaw operator so as to maintain its beauty.
Forestry England works supervisor, Steve Orton, describes the felling of the ‘Big Ben tree’ as a huge honour for the chosen operator.
And as Kielder is one of the few places in the UK that can supply tall, high-quality trees, the team take seeds from previously selected trees and then plant the saplings at carefully recorded locations.
Steve added: “We reckon that by the 2050s some of these thoroughbreds will be ready to take their place at prime spots, including at Westminster.”
3. It's sustainable
For the last two decades, the sustainable and homegrown Christmas tree that takes its traditional place in New Palace Yard has been gifted to Parliament by the Forestry Commission.
All Forestry Commission trees are sustainably grown on plantations in the UK and are grown especially for the Christmas tree market.
They are harvested between six and ten years old and for every tree felled at least one is planted.
4. It’s more than 40ft tall
This year’s tree is 42 feet tall, weighing around 1.8 tonnes. That means it’s about the length of one and a half London buses - though much lighter.
In January the trees are recycled and sent to be chipped for use in composting.
5. It's not the only tree on the Parliamentary estate
Smaller trees are also supplied for the Speaker’s apartment and Westminster Hall.
The Speaker’s tree is around 25 feet, and the one at Westminster Hall is smaller.
The trees travel 330 miles south overnight on a low loader truck and then readied with lights before a grand switch on, which takes place in November.
6. There have been four Commons Speakers since Forestry England first started supplying Christmas Trees
These include Betty Boothroyd, Michael Martin, John Bercow, and the current Speaker of the House, Sir Lindsay Hoyle.
7. How much does it cost?
While the tree is gifted, costs incurred include transportation and decorating, which costs between £8,094 and £12,099 between 2012 and 2017.
Costs in 2018 were higher than in previous years due to the need to replace broken Christmas lights, higher cost for tree transportation, including moving it in and out of the Parliamentary Estate, relocating one tree on account of ongoing works and events, and a requirement for additional health and safety measures in Westminster Hall due to ongoing works.
These additional costs saw installing the tree that year rocket up to £25,886.58.
