The Democratic Alliance (DA) says government seems to have extended the national lockdown under the guise of easing the restrictions.
The opposition party was reacting to the release of regulations under Level 4 of the nationwide lockdown.
The DA believes there is no difference between Level 4 and Level 5 of the lockdown, which is coming to an end midnight on Thursday, and that some of the decisions by government were "draconian".
On Wednesday night, Cooperative Governance and Traditional Affairs Minister Nkosazana Dlamini-Zuma announced a new set of regulations under the eased lockdown. These come into effect on Friday.
Among the amended regulations is that people can exercise outside their homes, but only between 06:00 and 09:00 and that no one should be roaming the streets between 20:00 and 05:00.
The eased lockdown has also given people a once-off allowance to move between provinces, should they need to move "to the provinces where they are employed".
But the DA believes if government had used its proposed smart lockdown proposal, more of the economy could have been opened without compromising safety.
"Ultimately, there is not enough to distinguish lockdown Level 4 from Level 5. This will be disastrous for millions of lives and livelihoods.
"Government's approach is unnecessarily blunt and restrictive, with simply no justification for many of the arbitrary rules and restrictions," the party's interim leader John Steenhuisen said in a statement on Wednesday night.
The DA's proposal offered an incentives-driven approach, which the party believed would have empowered employers, employees and customers of businesses within a set of safety rules.
It adds that government's "unreasonable approach", however, may undermine the response to the pandemic by generating an explosion of non-compliance by people.
"The DA's approach incentivises businesses and people to comply, maximising jobs and tax revenue. Government's forces many to remain closed, potentially forcing them underground – to trade illegally or die.
"By way of example, no one will now be able to legally sell or pay for a haircut, which will have devastating consequences for many working class people who run salons and barbers out of their homes to support their families."
President Cyril Ramaphosa, during his announcement of the phasing in of the economy last week, said the sale of tobacco would be permitted, but that changed on Wednesday night when Dlamini-Zuma released the regulations. The DA also believes the banning of smoking and the sale of hot food was "draconian".
"Others are simply irrational – not based on a consideration of public safety at all, which is the whole purpose of a lockdown. E-commerce (online shopping with delivery) for example, is not allowed.
"Other countries are looking to e-commerce to keep their small businesses afloat, save jobs and service customers. Here we've chosen arbitrary ministerial diktat over harnessing individual creativity and decision-making."
While other restrictions such as a ban on alcohol were well intended, they will have severe negative unintended consequences, the party added.
It also intends to challenge the legality of a curfew.
"President Ramaphosa's Cabinet seems to be indulging in all its nanny-state fantasies. It may soon find itself having to justify these in court, where reasonableness still prevails."