The British National Party will find out on Friday if its decision to end its whites-only membership rule means it complies with race relations laws.
The party voted last month to let black and Asian people join.
London Central County Court will give a judgement on whether the change means the party now complies with the law.
The BNP has not revealed the exact nature of its membership change, but it is thought it has removed references to "indigenous British" people.
This would pave the way for black and Asian people to be admitted to the party for the first time.
BBC News