The Egyptian Trade Union Federation (ETUF) is organising an indoor rally on Tuesday for its members to back President Abdel-Fattah El-Sisi in the upcoming presidential elections in March.
The federation, which was founded in 1957, had earlier called on El-Sisi to run for a second term.
Tuesday's gathering will be held at the federation's Workers Social Club in Shubra El-Kheima in northern Cairo.
The presidential elections will be held on 26-28 March, with a run-off vote scheduled for 24-26 April if no candidate wins a simple majority in the first round.
The head of Ghad Party, Moussa Mostafa Moussa, emerged as the sole candidate to run against President El-Sisi in the election after he submitted his candidacy papers just minutes before the deadline on Monday.