President Mugabe was in contempt of the Constitutional Court by making the proclamation knowing that the same court had ordered that any by-election processes should be done after July 31, lawyer Tendai Biti has argued.
The disclosure came Tuesday after Mwenezi East member of parliament Mr Kudakwashe Bhasikiti made a fresh urgent chamber application at the High Court to stop the Nomination Court for the by-election in his constituency set for July 20 this year.
Mr Bhasikiti, is seeking to set aside Proclamation Number 7 of 2015 that set the Nomination Court date as July 20 and the by-election date as September 19 2015.
He argued that all election-related processes should be done after July 31, when his challenge against dismissal from Zanu-PF would have been finalised.
The Constitutional Court recently ruled that electoral processes will be done after July 31.
The proclamation was published at the time the High Court was deliberating on the preliminary points raised in the case in which Mr Bhasikiti is contesting the legality of his expulsion from the revolutionary party.
President Mugabe and the Zimbabwe Electoral Commission were listed as respondents while Zanu-PF was only cited as an interested party in the matter.
Mr Bhasikiti wants the court to condemn the actions of President Mugabe in making the proclamation as unconstitutional.