The Lions and South Africa Rugby have jointly urged the World Rugby to reconsider their decision on Franco Mostert’s move to Gloucester.
The Cherry and Whites announced the signing of the Springboks international at end of May but Lions straightaway disputed the move on the grounds of "irregular player movement".
By November, the South African board and Lions complained to World Rugby on the signing as they claimed that the negotiations between Gloucester and Mostert began at a time when the 28-year-old was contracted to Johannesburg outfit.
However, to Lions' disappointment the governing body ruled that Gloucester did not commit any wrong in securing the services of Mostert which did not go well with the South African board as they went on to appeal against the decision.
Mostert, who has made 29 Test appearances for South Africa joined the Kingsholm unit on 1st November when the 2018 Super Rugby season came to an end and made his debut for the club during the recently concluded Gallagher Premiership game against Worcester Warriors where he came off the bench in the 72nd minute.