Strictly Come Dancing's performances for week four have been revealed, with Frankie Bridge and Steve Backshall talking about how they're getting on in training.

This week, Frankie and partner Kevin Clifton will take on the Cha Cha to Carly Rae Jepson's Call Me Maybe and the couple told Zoe Ball on Strictly spin-off show It Takes Two that they had been struggling.

Frankie said: "I've been really nervous about doing the Cha Cha for ages and now it's actually here, it's really hard. It's so technical... I just don't get it - all the straight legs... It's driving me mad."

Kevin revealed: "Like the Paso, it's a dance that she's struggling with. Every week it's not like Frankie just comes into training and goes, 'Oh yeah, I can do that.' It's a real process to get to Saturday night and it's the same now, we're in a phase where Frankie's going, 'I don't know if I can do this'.

"But I'm starting to have some real faith in Frankie, especially after Saturday."

Meanwhile, Steve and his partner Ola Jordan are tackling the Salsa to Harry Belafonte's Jump In The Line.

Steve admitted even his well-built arms were straining to get through the lifts: "The first time I did a lift I was like, 'Boom, I could own this, she's really light,' and the second time I was like, 'Argh!' By the time you've done it 20 or 30 times you are wasted.

"My arms are too tired for armography. I've been lifting her 40 times a day, I can barely lift a cup of tea."

Ola added: "I think it's very hard to come back after Jake (Wood) and Janette's (Manrara) Salsa because it was such an amazing dance that it's going to be very hard to come back and top it, but we're going to give it a go."

Other dances this weekend will include Alison Hammond and Aljaz Skorjanec dancing the Samba to Bootylicious, Caroline Flack and Pasha Kovalev's Quickstep to We Go Together from Grease, and Jake and Janette's Jive to Elvis Presley's All Shook Up.

Scott Mills and Joanne Clifton will dance an American Smooth to Bonnie Tyler classic Total Eclipse Of The Heart, and Tim Wonnacott and Natalie Lowe have a Paso Doble to Tina Turner's The Best.