Brooke and Adalyn Lowe, from Douglas, Lanarkshire, are set to don their costumes for a school party on Friday, October 30.
Mum Heidi Strickland spent two weeks scouring the internet for the finishing touches to the hilarious outfits just in time for the party at Douglas Primary.
Mum-of-three Heidi, 30, said: “They’re normally really close but they’ll be rivals on the day.
“We came up with the idea because we’re just seeing Nicola and Boris everyday at the moment – we thought it’d be fun and make people laugh.”
Sturgeon fan Brooke, nine, pulled rank on her eight-year-old sister Adalyn who will go as the First Minister.
Heidi said: “Brooke likes Nicola so she said she was definitely going to be her – Adalyn was just like ‘ok’.”
Brooke will be kitted out in a wig, red dress and black jacket with SNP and Yes badges pinned to it.
Suit-wearing Adalyn, meanwhile, will don a blond wig for Johnson’s signature hairstyle while her ensemble includes the PM’s customary rucksack and cycling helmet.
And the pair are even getting into their roles by practising mimicking the respective leaders.
Heidi said: “Brooke has been saying ‘Frank, get the door’ from the Janey Godley sketch.”
And she added: “Most of the costumes came from eBay and Amazon over a couple of weeks – it was quite cheap to do.”
But big brother Conlan, 11, is less keen to join in.
Heidi said: “He thinks he’s a bit past that now – he keeps asking them if they’re not embarrassed.”
The excited sisters are now all set to impress their friends at school on Friday.
Heidi said: “It’s a bit of fun and it’s good that the school is still putting stuff on for the kids.
“It’s a shame because it’s not been easy for the kids.”