Tottenham is challenging the decision to hand the Olympic Stadium to West Ham after the 2012 London Games.
The Olympic Park Legacy Company selected West Ham over Spurs as the preferred tenant of the 486 million pound ($777 million) venue in east London.
Tottenham said on Wednesday it is questioning the legitimacy of the decision and has sent letters to the OPLC and the British Government, "raising concerns with the processes which led to the award."
The OPLC said it has received from Tottenham "a letter before action in relation to potential judicial review proceedings."
The Olympic body says "we are confident that if these judicial review proceedings are pursued, our approach will be entirely vindicated by the courts."