Mary Berry says she is expecting ‘sheer perfection’ from the contestants as the heat rises for tonight’s final of The Great British Bake Off.

Contestants Richard Burr, Luis Troyano and Nancy Birtwhistle will go head to head in the climax of the BBC1 series as skill levels reach a new high.

Mary – who judges the hit show with Paul Hollywood – said of the finale: “The tension and pressure of a final will really test the remaining three bakers. The bakes will have to be more and more elaborate as we go to a new level.

“The result has to be sheer perfection. I think this is going to be the most exciting final we have had so far.”

Meanwhile, favourite Richard Burr, 37, admitted the practical skills from his day job as a builder have been a huge help on the show.

He revealed: “I suppose I am known as the baker with the pencil behind his ear. It’s not an affectation it is just a habit from my day job as a builder. With attention to detail, you always need to write down measurements and dimensions, to be fairly precise and it’s the same in baking.

“Plastering comes in handy when you are smoothing out the top of a Dobos Torte. I found being in the tent is very similar to being on site, you are surrounded by tradesmen doing their jobs well, except it was just a lot cleaner and less swearing.

“I used to get away with just bringing biscuits in to work, but now they know what I can do I have to bring more interesting bakes in.”

Retired GP surgery manager Nancy Birtwhistle, 60, revealed the skills she has perfected on the show helped her to make her daughter’s wedding cake.

Nancy revealed: “I am self-taught, but I was so proud that I had learned to cover a cake in icing without any creases. As I knew I was going to be making my daughter’s wedding cake, I had been practising making sugar roses and even learning from You Tube. You have to keep trying – it’s no good just reading from a book.

“I made the wedding cake this summer for my daughter, the ceremony was at our local church and we had the reception at home. All the family have been so supportive of my time on Bake Off and I think there is a bit of reflected glory in there. “

Graphic designer Luis Troyano, 42, has told how he has used his family to road-test his recipes.

He said: “Throughout the series I used the family as guinea pigs completely. They are very rarely going to be rude and prefer to be complimentary, but their body language and their expression is always the true reflection if it is really rubbish.

“I was absolutely ecstatic to reach the final, I feel really happy that I have got to this stage. Regardless of the outcome, all your family and friends are so proud that you have done so well – just to have survived 10 weeks in the tent is a huge achievement. The time went by in the blink of an eye, it was so quick.”

The Great British Bake Off final screens at 8pm on BBC One.