JOHANNESBURG, July 7 (Reuters) - South Africa"s former president Jacob Zuma asked the Constitutional Court on Wednesday to suspend its order to the police to arrest him by midnight pending the outcome of his challenge against a jail sentence for contempt. The constitutional court gave Zuma a 15 month jail term last week for defying an instruction to give evidence at an inquiry into corruption during his nine years in power until 2018. read more He denies all wrongdoing. Zuma, 79, had been given until the end of last Sunday to hand himself in, and police had been instructed to arrest him by the end of Wednesday if he failed to do so. The state"s response to Zuma"s latest act of defiance -- after years of allegations about corruption and sleaze -- has been seen as a test of post-apartheid South Africa"s ability to implement the rule of law. Last Friday, Zuma asked the constitutional court to cancel his sentence on a number of grounds including the risk of catching COVID-19, an application the courts agreed to consider. Then on Tuesday he approached the lower high court requesting an order to prevent his arrest until that application is heard. The high court has not responded to Zuma"s request -- the presiding judge has said he will rule on it only on Friday, at 11.30 a.m. (0930 GMT). That means that, as things stand, the police must still arrest Zuma by midnight. In a letter to Acting Chief Justice Raymond Zondo, Zuma"s lawyer Mongezi Ntanga said the order should be suspended pending either the high court"s Friday ruling or the constitutional court hearing on his challenge set for July 12. "We understand that the constitutional court may direct the suspension of its orders, which if granted would be binding on the high court, to prevent our client from being arrested prior to all legal processes being finalised," Ntanga said. A spokesperson for the office of the Chief Justice declined to immediately comment. Zuma denies there was widespread corruption under his leadership, but has refused to cooperate with the inquiry chaired by Zondo, one of the country"s top judges.