Great Britain will compete in water polo at an Olympics for the first time in 56 years at London 2012.
The British Olympic Association (BOA) has confirmed it will allow the sport to take host-nation positions.
GB women's captain Fran Leighton said: "It's brilliant. We're happy the boys will compete alongside us and thankful to everyone who's supported us.
"All of our hard work has paid off and we 're now focused on being the best we can be in London."
The BOA is aiming to support a team of 550 athletes and around 450 support staff in 2012 but with its reported financial problems there have been fears that the organisation would look to make cuts to this number, meaning some of the lower-profile sports could lose out.
"Teams do cost more money but if we're serious about being a world-class performing nation we've got to take some of these team events and really start working on them," British Swimming chief executive Dave Sparkes told BBC Sport.
"I believe water polo can be one of the star events at the Games."
Water polo joins indoor volleyball, handball, table tennis, weightlifting and basketball (subject to approval from the governing body) in being guaranteed host-nation places for 2012.
Sir Clive Woodward, Team GB deputy chef de mission and BOA director of sport, said: "The commitment and results that both the water polo teams have shown, and innovative plans developed for water polo, demonstrate that the players will make the nation proud in 2012 and leave a long-term legacy."
The "commitment" Woodward refers to has been considerable to say the least.
Although Great Britain did not enter a team at the 2008 Beijing Olympics, they were still given a budget of £3.14m to develop the sport.
However, in the lead-up to the London Games this was initially slashed by over 50%, resulting in those from the men's programme being forced to look abroad for full-time professional contracts.
In December 2009, water polo - along with 10 other Olympic sports - received a funding boost, raising their 'pot' closer to that which they received prior to the 2008 Olympic Games.
The women's team have subsequently embarked on fortnightly trips into Europe, where they compete in the Hungarian national league in order to gain experience against world-class opponents.
"Both the women and the men have gained valuable experience playing regularly in Europe and have now increased their performance to a level at which we are confident that they will perform credibly in the pool come 2012," said BOA chief executive Andy Hunt.
"London will also be an experience that the British players will be able to capitalise on for their future development towards the Rio 2016 Olympic Games and beyond, particularly the comparatively young men's team."
GB men's goalkeeper Ed Scott said it was "fantastic" news for both teams.
"It's the culmination of all the hard work and sacrifices every one of us has made," he said.
"Getting to showcase water polo on the world's greatest stage will hopefully encourage more people to get involved and help develop the sport throughout the country for years to come."
The sentiments were echoed by the sport's CEO David Sparkes.
"It's been a roller coaster ride for the athletes, funding switched on, funding switched off - they've had to work really hard but the commitment of both the men and the women has been absolutely unbelievable.
"We've got 18 months of really hard work with both the women's and the men's teams to make sure we get the best possible performance that we can in London."