What is the ruling on praying in a garment that has been stained with some impurity, and it is impossible to change it due to the unavailability of an alternative?

If clothes become impure and there are no other clothes available, and there is not enough time to wash them, then the issue is a matter of scholarly disagreement:

First opinion: One prays with the impure garment and then repeats the prayer if a pure garment is found or if one is able to purify their garment. This is the view of Ahmad, Malik, and Al-Muzani, and it is the preponderant opinion. Their evidence is that covering the 'awrah is more emphatic than removing impurity.

Second opinion: One prays naked, and there is no repetition of the prayer upon them. This is the view of Al-Shafi'i and Abu Thawr. Their evidence is that it is an impure covering in which prayer is not permissible.

Third opinion: If the entire garment is impure, then the worshipper has a choice between the two actions. This is the view of Abu Hanifa.