Christmas tree growers from across the ITV Meridian region are bidding for the chance to present the tree which will take pride of place at the official residence of the Prime Minister.
Over 100 growers will take part in a national competition organised by the British Christmas Tree Growers' Association in Oxfordshire today.
The event will see the hopeful contenders - who span in age from 18 to 80 - coming together to showcase their trees to expert growers, and be judged by fellow members.
Each farmer, who will have spent around 10 years nurturing the tree to full 'competition' height, is able to enter categories including Best Nordman, Best Other Fir, Best Pine, Best Norway Spruce, Best Other Spruce, Best Container Grown, and Best Festive Wreath.
Finalists can submit only one tree into each category, and trees entered must be commercially cultivated and be 1.8 metres high from base to tip. Each will be judged for foliage, colour, shape and marketability.
Following the verdict from the prestigious competition day, the winning grower will supply Downing Street's 20 ft Christmas tree, while the winner of the wreath category will create a wreath to hang at the front door of Number 10.