A group of 20 of Nicholas' family and friends will travel down to London this morning to cheer him on.
Last night his mum Eileen, 45, said: "The support from across Scotland has been overwhelming and we are just so grateful.
"The Tartan Army has really come together for Nicholas and we are asking them to do it one last time to get him over the final hurdle."
X Factor mania hit Scotland this week when Nicholas returned to his hometown of Motherwell, Lanarkshire.
The 17-year-old crooner paid a visit to his old school before heading to his mum's house where X Factor judge Louis Walsh joined him.
Crowds of fans and well-wishers packed into St Aidan's High School in Wishaw before lining the streets of Nicholas' hometown as he returned for a visit.
He later wowed adoring fans in a special one-off show at the Motherwell Civic Centre.
Proud Eileen added: "We have seen how the country has come together following the helicopter crash in Glasgow and the support we have had makes me so proud to be Scottish.
"That really put things in perspective and it's so touching that people still picked up the phone to vote.
"It's the public who have got him to this stage and I hope everybody picks up the phone this weekend to make his dream come true."
Nicholas made it through to the show's final last weekend and is still on course to land the X Factor winner crown.
He will compete in the finals against prison officer Sam Bailey and 17-year-old Luke Friend.