South Africans are not expected to hear the disappointing "system offline" response when they register to vote this weekend, the Electoral Commission of South Africa (IEC) has assured.

The IEC held a dry run on 28 October to ensure that registration weekend runs smoothly, the Portfolio Committee on Home Affairs heard on Tuesday morning.

Deputy chief elections officer Mashego Sheburi said voter registration devices had been updated with new operating systems, and had been optimised to default to offline mode if connection with a database can't be established.

In offline mode, the data is stored on the device and only transmitted when a stable connection has been established to the network, and where connection to databases has been restored. In instances where there is a connection delay, the devices will switch to offline mode within five seconds.  

Inkatha Freedom Party MP Liezl van der Merwe asked what guarantees the IEC had that there wouldn't be any glitches in cases of load shedding, for example, or in rural areas where there is limited connectivity.

IEC chairperson Mosostho Moepya said when a voter's ID is scanned, that information is stored on the machine and is kept until it is safely downloaded. No information will be lost when the devices are offline.

If there is loadshedding on Saturday and Sunday, it will not impact their work.

In the past, concerns were raised about the use of SA Democratic Teachers' Union (Sadtu) teachers' union members to temporarily staff the IEC.

The Economic Freedom Fighters said in a statement on Tuesday that its "ground forces" would be "vigilant and ensure that they identify any affiliates" of Sadtu. 

The party said the union was an affiliate of the African National Congress, and alleged that its members were "unfit to be the custodians of a democratic election".

However, Sheburi said the commission used recruitment criteria approved by the national party liaison committee - on which all parties in Parliament are represented. Nothing in the IEC's staffing criteria or policy states that the IEC will only recruit teachers at the exclusion of anyone else, or teachers affiliated with a specific union.

"It would be unlawful and unconstitutional to exclude a class of people from working purely because they are teachers or belong to a specific union," Sheburi added.

Furthermore, they also test the ID numbers of the list of candidates and vet them for criminal offences.

Moepya added that voting stations must work and that the IEC requires capable people to manage them.

The committee was generally appreciative of the IEC's preparations, although the low turnout among young people is a common concern.

The IEC is creating its own content on social media platforms – albeit that its research shows young people take the information they receive there with a pinch of salt and are not swayed by influencers – and are making use of traditional advertising methods as far as their budget allows.

Another registration weekend is envisaged, but the date will only be announced after the date of the election has been proclaimed.

Overseas voters will be able to register for three days in January.