Southern Kings president Cheeky Watson has hit out at the SA Rugby Union (Saru) for guaranteeing them in Super Rugby for one year instead of three years.
The Kings were told in January that they would be included in Super Rugby from 2013 but had to wait until today to find out who they would be replacing and the conditions of their inclusion.
Saru announced on Thursday that the Kings would play in the 2013 Super Rugby competition, with the Lions dropping out for at least one year.
The Southern Kings can ensure that they remain in Super Rugby by finishing ahead of the last placed South African Super Rugby team.
"I think it is a ludicrous decision," Watson said after the decision was made at a Saru general council meeting in Cape Town.
"It doesn't make sense in rugby, not in business, not in the church.
"It doesn't make sense in any sector of society that you are sitting with a scenario that you are in Super Rugby for one year and expected to achieve.
"But I think we, as the South Eastern Cape, play the hand that we are dealt and we make the best of it."
Later Watson was speaking to Ballz Radio and said that the decision "cannot be accepted" and that they will appeal to SARU to be included for three years.
The top four teams in the South African Conference in 2012 - the Stormers, Bulls, Sharks and Cheetahs - would join the Southern Kings in the 2013 tournament, Saru announced, seven months after the proposal was first tabled by the executive council.
The Lions, who dropped out as the bottom team in the SA conference this past season, would have a chance to regain their status in 2014.
"Obviously we are very disappointed," said Lions president Kevin de Klerk.
"We had hoped the immense amount of work that we did in the background - ourselves and with Saru - would have culminated in a better result."
De Klerk, however, was pleased that the Lions would have a chance to regain their place.
"This is effectively a four or five month exit to the Super Rugby process, whereby this competition will be revisited in terms of a playoff scenario, and we will contest that - should we still be around at that stage - most vigorously."
Saru confirmed that the promotion/relegation playoff would also be in place in 2014 and 2015, at which point the broadcast rights contract expired and a different format could be considered.
Saru president Oregan Hoskins said the decision to include an Eastern Cape franchise in the Super Rugby tournament was first made in 2005, but was twice postponed.
"All rugby provinces have been consistently in support of the need for an Eastern Cape team in the Super Rugby competition," Hoskins said.
"We made a commitment to the Kings to include them in 2013 and rugby has delivered on that commitment.
"The franchise represents more clubs than any other region - apart from the Stormers - and contains numerous leading rugby schools.
"It has been starved of top-class rugby competition for a decade-and-a-half and now it has the chance to show what it can do."
Hoskins said Saru and the Kings had wanted a "rugby solution" to accommodate six franchises in five places and Thursday's announcement had delivered on the promise, as hard as it was for the relegated team.
"The provinces asked for a rugby solution and we believe that this was the fairest and most transparent method to respond to what is undoubtedly a less than ideal situation," he said.
"We also canvassed Super Rugby players before the start of the season, through the Players' Association, and this was their preferred mechanism.
"We will continue to push the case for early expansion within Sanzar.
"Negotiations on a new broadcasting rights deal will begin shortly and the inclusion of six South African franchises will be firmly top of our agenda."