Who presents the Christmas tree to No. 10 Downing Street?

This news items suggests that "Christmas tree growers across the country decide":

One of the most famous addresses in the country is being lit up by a Christmas tree from Herefordshire this year.

A Norwegian spruce from Dinmore Nursery Christmas Trees was voted the best tree to be put up outside 10 Downing Street in London.

The honour was awarded to Colin Griffiths who had been growing the tree since 2000.

Christmas tree growers across the country gather to choose which tree should go outside the famous house.