Animal health inspectors of the Welsh Assembly Government are scheduled to reach the Skanda Vale Temple on Thursday morning to collect Shambo, the sacred bullock, for slaughter, according to temple officials.
The Court of Appeal this week upheld the Welsh Assembly Government's order to put it down in line with animal health regulations.
Brother Michael of the temple said: "The news could not be worse for the temple and Hindus around the world. For the last three months or so we have looked at every conceivable option to find an alternative to killing.
"Unfortunately, the Welsh Assembly has been so blinked that it can only see destruction. The Assembly and the National Farmers Union have contrived to misinform the public as to the extent of the problem.
"I reiterate that Shambo remains healthy and shows no signs of bovine TB. Tomorrow morning inspectors will be taking a perfectly healthy animal away, destroy him just on the assumption that Shambo could have bovine TB. How ridiculous is that?"
He added: "We will be holding a pooja in the morning, praying for the life of Shambo and the sanctity of all life. Our religious laws prevent us from assisting in the killing of any life and so we will not help the inspectors remove Shambo.
"He will remain in his enclosure and they will have to physically desecrate a temple and an act of worship to get him. As registered place of worship we will undertake our legal right to worship God. The Welsh Assembly Government will have to interrupt an act of worship.
Ramesh Kallidai from the Hindu Forum of Britain added: "The main issue is that the judiciary and the government have stated that it is acceptable and proportionate to commit the highest act of sacrilege against the Hindu religion by desecrating our temple and slaughtering a sacred temple animal.
"They said that they will deal with the slaughter in a sensitive manner.
However, when we requested for a second test for Shambo, they rejected it immediately. This demonstrated that they really did not mean to be sensitive in action, but only words.
"The whole process is an alarming and I fear that his matter will seriously set back relations - both nationally and internationally - between the Hindu community, politicians and the government."