Diolch, Dirprwy Lywydd. May I congratulate David Rees, Leanne Wood and Vikki Howells for bringing forward this debate? As their motion recognises, there is significant potential in the network of historic industrial infrastructure across Wales, in particular the old railway tunnels across the south Wales Valleys, that can serve the communities that surround them once again, providing important economic and social infrastructure.

But as the motion also notes, bringing them back into use does pose very real, practical and financial challenges. There are successful examples we can point to where the legacy of our industrial past has been harnessed to bring benefits today. The Ffestiniog railway and the Pontcysyllte aqueduct are examples of outstanding heritage assets that attract tourists and generate local employment, as well as telling the story of the past. We've recently announced funding through the Valleys Regional Park for £7 million for gateways to the Valleys Regional Park that will add to that too. Of course, these were not regenerated into the jewels they are today overnight, but as we look at other opportunities to bring the legacies of our industrial heritage back to life, we need to remember that Blaenau Ffestiniog wasn't built in a day.

Members have spoken persuasively this afternoon about the potential that the network of old railway tunnels across south Wales have as transport corridors, as Mick Antoniw has just mentioned. Other former railway lines have had a new lease of life as walking and cycling routes. The Taff trail, for example, between Brecon and Cardiff, and the Ystwyth trail, which connects Aberystwyth with Tregaron, are excellent examples.

I don't need any persuading to support the principles of the motion. Indeed, I was involved some 10 years ago in the scoping exercise that looked at the potential that these tunnels have for changing the dynamics of travelling between the Valleys. The fairly direct and flat routes that visionary engineers bored through our mountains, to carry trains in the industrial age, can help re-engineer the way we think about travel in the modern era. Even an electric bike over the Merthyr mountain may be asking a lot of most people, but a quick, direct route under it is an altogether more realistic ask—but only if the tunnels are linked up to a network of paths that connect destinations that people want to travel to. After all, active travel is about replacing car journeys with cycling and walking for everyday trips. To meet the challenge of the climate emergency, we need to replace car trips with zero or low-emission alternatives as quickly as possible.

Our priority, therefore, must be to put investment where it can have the quickest and most significant payback. Often, a mundane contraflow down a one-way street or a wider pavement may change an environment to make walking and cycling a visible option. In other cases, a harder engineering intervention like a segregated cycle path on a main road, to separate bicycles and cars, is what's needed. Having recently ridden down Cardiff's Senghenydd Road, I can testify to the dramatic impact that the segregated cycle lane being constructed there can make. I'm sure that once that route is completed, we'll see a very big increase in cycling in that part of the city.

So, we need the right infrastructure in the right places. Alongside it, we need training and promotion to bring about a culture change. As we look at the suite of interventions needed to bring this about, I'm in no doubt that the network of old tunnels has its part to play. But with limited resource, we have to prioritise. Today's motion asks the Welsh Government to take into our ownership this network of tunnels, and then to seek funding opportunities. I have to say to Members that I cannot support this approach. In my view, it is the wrong way around. Taking on the massive liabilities of these old tunnels would involve a very big investment of money and capacity at a time when our focus needs to be on getting early wins for the active travel Act. In themselves, the tunnels will not bring about modal shift, which must be our focus as we look to meet our very ambitious carbon reduction targets. They can play a part, but only in an integrated approach.

The active travel Act, which was passed by this Chamber six years ago this week, sets out an approach to creating a network of routes—