The United Democratic Movement (UDM) has added its voice to those of politicians calling for the urgent debate of a motion of no confidence against President Jacob Zuma.

The party on Monday wrote a letter to the Speaker of the National Assembly, joining calls from the Democratic Alliance for an urgent sitting to debate the motion.

"With his unmotivated, seemingly unilateral - and ultimately irresponsible and reckless - Cabinet reshuffle, the president of the Republic of South Africa, Mr JG Zuma, has effectively relegated the South African economy to junk status," UDM chief whip Nqabayomzi Kwankwa said in the letter.

He questioned whether Zuma had considered the consequences of his decision.

"South Africans will soon feel the pinch, but ultimately the poorest of the poor will be hardest hit when food, transport and other necessities become unaffordable," the UDM said.

"The United Democratic Movement adds its voice to that of our colleagues in other parties, and calls on you to schedule an urgent special session of the National Assembly to debate a motion of no confidence in the president in terms of section 102 of the republic's Constitution, as well as section 129 of the rules of the National Assembly."

'Motion from opposition will unite ANC'

The Freedom Front Plus' Dr Pieter Groenewald said while the party would support any vote of no confidence against Zuma, this had to be considered strategically.

"The correct strategy would be to give the ANC the opportunity to try and rally support internally through which a vote of no confidence in Zuma could be introduced by ANC members of Parliament."

A vote of no confidence from the opposition would unite members of the ruling party, Groenewald said.

"The ANC will not allow the impression that an opposition party succeeded in having the president removed. A motion from the opposition will be a futile exercise. Members of opposition parties should rather focus on confidentially rallying ANC MPs to introduce a vote of no confidence in Zuma."

Speaker Baleka Mbete is due to make a decision on the matter this week.