In an open letter to fans, chief executive Richard Holland explained that they would no longer be pursuing that option, be it temporary or permanent.
His letter said:
“I am writing on behalf of the Cardiff Blues board to update you on the dialogue that has been taking place between ourselves and our governing body, the Welsh Rugby Union, and on negotiations with Cardiff Athletic Club regarding a lease extension at Cardiff Arms Park.
“It was mentioned at the recent AGM by myself that talks had taken place with the WRU to explore how they could assist us during the potential redevelopment of Cardiff Arms Park, which led to further discussions regarding taking control of the rugby operation both on a temporary and permanent basis. The board wanted to fully explore all options available to them and to decide on the best way forward.
“Following amicable discussions with our governing body, I can now confirm the Cardiff Blues board have made the unanimous decision not to pursue this option further.
“I would like to add however, our relationship with the WRU is as strong as ever and along with Martyn Phillips (WRU CEO) and the other regions’ CEOs, we will continue to explore the best way forward for the future of professional rugby in our region and in Wales.
“With only five years remaining on the existing lease and the annual costs of maintaining the current facility escalating, the Cardiff Blues board are resolutely focused on extending the lease and redeveloping Cardiff Arms Park to provide a fit for purpose stadium for both Cardiff Rugby Football Club and Cardiff Blues.
“The history and heritage of Cardiff Rugby at Cardiff Arms Park is of paramount importance to the board and it is essential to protect all elements of this great club and its iconic home.
“We remain in ongoing negotiations with Cardiff Athletic Club regarding the granting of a new 150-year lease with development rights and are very hopeful of an agreement with the CAC management board.
“I am currently in the process of scheduling a meeting to agree the legal terms with CAC management representatives so they can call an EGM to vote on the matter.
“It is my intention to write to all CAC members outlining the key elements of the legal documents being negotiated.
“I will also share with members some potential concept ideas for the redevelopment. These concepts are purely an indication of what could be achieved, from the replacement of the North and South stands to a complete redevelopment of the entire site, with the playing of rugby being the priority.
“We will keep our key stakeholders fully updated on the progress. If approval is granted to trigger the option period we will form a working party to ensure the interests of all stakeholders are fully represented as we take things forward and develop a future home for both Cardiff RFC and Cardiff Blues at this iconic site.
“We thank you for your support and cooperation at this time and I will keep you updated as matters progress with Cardiff Athletic Club.“