Mark Drakeford gave a two-word response when asked if the Welsh Government will be reversing their default 20mph speed limit law.
It comes as a petition calling on the Welsh Government to reverse the policy on new speed limits has reached over 170,000 signatures - far more than double the previous record.
On Sunday 17 September, 30mph roads were reduced to 20mph where cars mix with pedestrians and cyclists. It is thought around 13,000km of road will be affected.
The move has proved controversial with a poll for ITV Wales revealing this week that just 31% of people support the policy, while 66% are opposed to it.
During First Minister's Questions in the Senedd, Conservative MS Tom Giffard asked Mark Drakeford whether he would "rescind his disastrous 20mph scheme".
He replied: "No, Llywydd."
The First Minister elaborated shortly afterwards in response to Labour MS Alun Davies.
He explained the reason for the chang "is the lives of the people who would have been caught up in those road traffic accidents that won't happen when people drive at 20mph, that would have if they were to drive at 30[mph]."
He said: "That is why this government will be sticking fast to the decision that has been made, endorsed twice on the floor of this house by a super majority.
"[It's] because of the human stories that lie behind the decision we have made and will continue to implement [it]."
The Welsh Conservatives have thrown their support behind the petition, with one MS saying sticking with the policy will lead to people questioning democracy in Wales.
Speaking with ITV Wales on Monday, Shadow Transport Minister, Natasha Asghar MS said: "It's so important that it's reflective of the democracy we live in.
"People are really questioning the legitimacy of democracy that's happening in the Welsh parliament, and that causes me concern and I know it causes a lot of people who are out there concerned too."
A Welsh Government spokesperson said: “The introduction of a default 20mph speed limit is a policy which has received cross party support in the Senedd.
“Reducing speeds reduces collisions and saves lives but also improves the quality of life – helping to make our streets and local communities safer for everyone."
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