The arrangement has been made with the convenience and safety of athletes in mind, given the COVID-19 pandemic, and the competition is being undertaken amidst strict medical protocols.

Of the 72 quota places for this summer’s scheduled Olympics, 26 have still to be claimed, so there will be all to play for when four days of competition get underway tomorrow with qualification for the women’s final on Saturday (April 17). 

Friday (April 16) will see qualification for the men’s final on Sunday (April 18).

Six automatic quota places - three for women and three for men - will be on offer during the seasonal showpiece of the UIPM 2021 Pentathlon World Championships that are due to take place at Cairo in June.

Between now and then, athletes competing in Sofia can earn points to qualify for the UIPM 2021 Pentathlon World Cup Final in the Hungarian venue of Szekesfehervar in May, where more qualification points for Tokyo 2020 will be available to the 72 participating athletes.

Having won three of the six medals on offer so far this season, Britain’s women are again strongly represented by two athletes in the top five of the UIPM Olympic world rankings.

Joanna Muir and Francesca Summers will lead a women’s team of four with world number two Kate French sitting this competition out.

Competition for the two available places at Tokyo 2020 is tight between three outstanding female athletes from Belarus, whose challenge will be led by Beijing 2008 bronze medallist and 2018 world champion Anastasiya Prokopenko and Iryna Prasiantsova, with 2019 world champion Volha Silkina absent.

London 2012 champion Laura Asadauskaite of Lithuania finished in the top six at the first Pentathlon World Cup in Sofia  and she will be looking for a podium place alongside team-mates Gintare Venckauskaite and Ieva Serapinaite.

Meanwhile, the 2017 world champion, Gulnaz Gubaydullina of Russia, and 2018 world silver medallist Annika Schleu of Germany, are also carrying high hopes of a prominent performance.

Competition has been wide open this season in the men’s events, with six different nations winning medals – and all six medallists are in action again this week.

Woongtae Jun of South Korea, winner at the first Sofia World Cup, will be one of the favourites along with team-mates Jihun Lee and Jinhwa Jung, who are also rivals in Tokyo 2020 terms, while Germany have four high-ranked athletes competing for two coveted Olympic places - brothers Patrick and Marvin Dogue, Fabian Liebig and Christian Zillekens.

Others likely to be in the mix are world number one Joseph Choong and his British team-mate Jamie Cooke, the 2018 world champion, Shuai Luo of China and Rio 2016 Olympic silver medallist Pavlo Tymoshchenko of Ukraine.

UIPM President Dr Klaus Schormann commented: "We had two successful competitions already in the UIPM 2021 Pentathlon World Cup and it has been so encouraging to see a huge number of athletes from all around the world gathering and competing at a very high level.

"With 100 days to go until the Opening Ceremony of the Olympic Summer Games Tokyo 2020, taking place in 2021, the athletes know that this is their time to shine and we are all looking forward to another exciting competition in the wonderful city of Sofia."