"It's best not to underestimate us," says a defiant Harriet Dart. But Great Britain's Billie Jean King Cup squad know full well the enormity of the challenge that awaits them. On Tuesday, the tight-knit British team - Dart, Katie Boulter, Sonay Kartal, Mika Stojsavljevic and Jodie Burrage - take on the Czech Republic in their BJK Cup quarter-final in Shenzhen, China.

GB have reached the semi-finals in three of the past four seasons, but in the Czechs they face the 11-time champions and an eye-watering line-up - the only team boasting two top-10 players at the Finals tournament. In Linda Noskova and Karolina Muchova, they have the current Wimbledon champion and her beaten opponent from this summer's all-Czech final. All five members of the Czech team are ranked higher in the singles rankings than any of the British squad.

"I think naturally we are definite underdogs," Boulter, the current world number 54, told BBC Sport. "We are the ones that are going to have to make something happen, something special. But that being said, a lot of pressure is on them, and we've seen in this tournament before that people can make upsets, and I think that's what we'll be looking to do."