Lee Waters will stand in the Senedd chamber on Wednesday and make a pitch to keep his job. The deputy climate change minister has been the face of the default 20mph speed limit for Wales.

A petition calling for the law to be rescinded broke Senedd records – it currently stands at 430,000 signatures – and as a result the Welsh Conservatives tabled a motion saying there can be no confidence in Mr Waters, who represents Llanelli for Labour. It is due to be debated around 5.30pm with a vote following later in the evening.

Mr Waters plans to speak in the debate. Speaking to WalesOnline about the 20mph law on Tuesday Mr Waters said he expected some roads to go back to 30mph. Councils have the power to exempt some roads from the default speed limit and allow them to remain at 30mph. He said there has to be flexibility going forward and once councils reassess their initial choices for exemptions then a number will go back to 30mph. He also admitted that confusion about what the law means is causing some drivers to drive slower than they need to but blamed that on the Conservatives calling it a "blanket" ban. If you want to read about the argument as to whether its a blanket ban we have an explainer here.

READ MORE:We interviewed the man responsible for Wales' 20mph limit

OTHER 20MPH NEWS:First Minister speaks of vile threats

The vote is highly likely to fail as Plaid Cymru plan to back the minister. Between them and Labour there are enough votes for it to fail. Plaid has criticised the Conservatives for "political gameplaying" but has also expressed disappointment at the way the policy has been rolled out. Despite that it plans to vote against the no-confidence motion. A Plaid Cymru spokesman said: "Plaid Cymru is supportive of the principle of introducing new 20mph limits to save lives and have consistently said that local communities should have a voice in how these safer speed limits are introduced. There are problems way this legislation has been implemented. It has not been well-communicated and there are inconsistencies in the exemptions that have been applied.

"That’s why Plaid Cymru called for communities and councils to be supported in reviewing new limits and seeking further exemptions if some new limits are deemed to be unreasonable in practice. We disagree with several elements of how the policy has been implemented but think it is the duty of the minister to address the concerns that have been raised.

"Political gameplaying from the Tories will not resolve this issue and we will not support their motion of no confidence. We urge all sides to listen to the genuine concerns of people right across Wales to reach a consensus that will give people a voice in the safety of their own communities."

Mr Waters has joined the First Minister Mark Drakeford, presiding officer Elin Jones, and leader of the opposition Andrew RT Davies in sharing stories of threats made to them over the debate with him admitting the police have had to be called to his home. Mr Waters said: "Of course it impacts me – I'm a human being. It's horrible but I also knew that this is going to be a difficult policy to take through. People have accused me of being arrogant or not sympathetic in my responses and what I'd say is that I'm confident of the evidence. We've worked really hard on this policy for four years. We haven't rushed into it – we've carefully looked at the evidence, we've tested it, we've worked with experts, and I think it's the right policy. And two-thirds of Senedd members think it's the right policy. That's why they voted for it twice."

He admitted the debate has become fractious. Last week the First Minister was reprimanded for the tone of the debate with the Conservative leader Mr Davies – you can read about that here. "It's been horrible and I genuinely think the way that the Conservatives have weaponised it, it's not surprising but it's really unpleasant," said Mr Waters. "It's confusing people. The reason why I think some people are not sure what speed the speed limit is and are going slower than they need to on some roads, and causing driver frustration, is because of this line that it is a blanket speed limit. It has gotten into the consciousness and it's not true. So not only is it unpleasant personally it's politically irresponsible."

Asked if he had considered quitting his job in the last week he said: "I have that conversation with myself most days – you know, this is not a fun job." He added: "I had to steel myself because I knew it was coming but it's been horrible for me and for my family but I'm not complaining about it and, you know, I was ready for it because I knew this was going to happen because as soon as you start doing things with people's cars people get really angry." When asked if he still expected to be the deputy minister for climate change by the close of Senedd business on Wednesday he replied: "Well if the Senedd members who supported this policy support its implementation then yes."