The two countries secured their spots in the final by virtue of winning their groups, with holders Switzerland, represented by Leandro Riedi and Celine Naef triumphing in Group One over Denmark and event hosts France.

In the Denmark tie Switzerland were on the back foot as Naef was beaten by Clara Tauson 6-2, 6-3 in the women’s singles match.

Riedi, the current world number 152, then upset world number six Holger Rune 6-4, 6-3 to level the tie in the men’s singles contest.

In the deciding mixed doubles match, Naef and Riedi teamed up to win 6-3, 7-5 against Tauson and Rune.

Switzerland then beat France at Nice Lawn Tennis Club, with the hosts taking the lead in the tie as Alize Cornet overcame Naef 1-6, 6-3, 10-8.

Riedi levelled the tie by defeating Richard Gasquet 3-6, 6-3, 10-8, before Naef and Riedi earned doubles glory by overcoming Cornet and Gasquet 6-4, 7-5.

Croatia’s pairing of Borna Ćorić and Donna Vekić won Group Two after defeating Spain and Belgium to finish top.

Against Belgium, things got off to a bad start when Elise Mertens dispatched Vekić 6-2, 6-2, before Ćorić levelled the tie by overcoming David Goffin 6-3, 2-6, 10-4.

Vekić and Ćorić combined for a decisive victory in the doubles, beating Mertens and Goffin 7-6, 3-6, 10-6.

In today’s final tie of the group stage against Spain, which would decide who faced Switzerland, Vekić overcome Rebeka Masarova 6-2, 6-1 in the opening women’s singles match.

Wimbledon champion and world number one Carlos Alcaraz, the highest-profile player at the event, then beat Ćorić 6-3, 6-7, 10-5 to send the tie the distance.

Croatia secured their place after winning a thrilling mixed doubles encounter, with Ćorić and Vekić coming from a set down to overcome Masarova and Alcaraz 1-6, 6-4, 14-12.

The final is due to take place tomorrow, over the same format of men’s and women’s singles, followed by a mixed doubles match.