A Welsh Government minister has accused the opposition of spreading "misinformation" about Sunday's 20mph rollout across Wales.
Deputy Minister for Climate Change, Lee Waters MS, said "conservative members are making false claims about this policy".
It follows a debate in the Senedd where the Welsh Conservatives described the speed limit change as a "blanket" policy.
The party's leader, Andrew RT Davies MS said: "The default position that, obviously, the government have taken, to have a blanket 20mph, is the wrong option, First Minister".
First Minister Mark Drakeford MS hit back and criticised him for using that description.
He said: "Well, there are a whole string of points to be corrected there.
"It is not a blanket policy. It is a default policy and then local authorities are able to designate roads at a 30mph speed where it is sensible for them to do so".
Lee Waters also insisted that it is not a blanket policy, saying "there is no blanket 20mph, as the conservatives wrongly claim.
"We are following the approach that the experts recommended".
What will happen and how will it work?
The rollout on Sunday will affect the majority of urban roads in Wales.
It will be in place on what is called 'restricted' roads, which include those where streetlights are placed no more than 200 yards apart and in residential and built-up areas with high pedestrian activity.
The policy aims to reduce the number of road traffic collisions, improve air quality and noise pollution, and encourage the shift away from car use.
Local authorities have the power to exempt roads from the speed reduction policy and maintain the 30mph limit. There will be 30mph signs in place to tell you if this is the case.
This is the reason ministers say that the policy should not be described as "blanket".
The Welsh Tories have been critical of the 20mph rollout. They say the policy is going to cause delays on the road and cost the economy more than £4 billion.
Speaking on Tuesday, Natasha Asghar MS said that not only is the scheme costly, it is unpopular.
"My inbox has been inundated, and I cannot underestimate and tell you how full it's been, with e-mails from constituents airing their concerns about the 20 mph limit going forward.
"You can all stand here today, specifically you, Deputy Minister, and say that the public are on board and perhaps support this move, but the reality is they do not support this move", she said.
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