A plan to create a London-style bus system for Wales will only work if backed by significant extra cash, the Welsh government has been warned.

A law putting buses back under public control, which could allow transport officials to decide what bus services are provided, is expected to be published on Monday.

Welsh Labour wants bus companies to bid for contracts instead of operating their own routes, following years of cuts and falling passenger numbers.

The proposals were first published six years ago, but could take another five years to deliver.

Since the mid-1980s, private companies have been able to run buses where they want, as long as they are registered and meet safety standards.

Critics say it leaves services vulnerable to being axed if they do not make a profit.

In London it works differently, with operators bidding for set routes laid out by Transport for London.

Details of how the Welsh government will change things are due to be revealed to the Senedd later.

But the Welsh government has previously said it wants to set up franchises overseen by the Transport for Wales (TfW) company, which it owns.

TfW would set the routes, timetables and fares with local councils. Companies would then bid to deliver the service for a fixed fee. As in London, buses could also be branded the same.

Other parts of the UK, including Manchester, have started introducing bus franchises.

Welsh ministers have promised a “simpler, connected and joined up public transport network”, replacing a system where bus companies set their own timetables and use different ticket systems.

But the government said last year the franchise contracts could put TfW “at risk from decreases in passenger fare revenue“.

Fewer passengers “will either require additional funding or making difficult decisions about reducing services”, the Welsh government said.

“It is right that these decisions, where necessary, be made in the public interest,” it added.

On Sunday, Transport Secretary Ken Skates told BBC Politics Wales tthe government was “taking back control over how routes and timetables operate”.

“This has never been done on a national scale before, so it is hugely ambitious,” he said.

“But I think it’s going to prove to be one of the most important pieces of legislation that we have ever taken through – to give better options to the whole of our country.”

Barclay Davies, from Bus Users UK, said franchising “can be great for passengers, but it’s not cheap”.

“It will require significant amounts of funding. That’s the issue at the moment – how much funding is available.”

He said TfW, which already runs the rail network, would need to “manage people’s expectations”.

“If the funding isn’t available they are going to have to cut their cloth accordingly, so you might not have the frequency of services that people want and expect.”

Essential services are already subsidised by the taxpayer, but the number of bus routes, vehicles and passengers has still declined.

People made 61 million journeys on local buses in 2022/23, compared to 91.7 million in the last full year before the pandemic.

The bus industry said it wanted contracts that “combine central control with a focus on customers and commercial incentives to deliver improvements”.

Aaron Hill, director of lobby group Confederation of Passenger Transport (CPT) Cymru, said: “Simply changing who’s in charge won’t guarantee success – passengers will only see better buses if commitments are backed by adequate funding, and by steps to speed up buses by taking them out of traffic congestion.”

Welsh Conservative shadow transport secretary Peter Fox said franchising bus services across Wales “comes with risks if not executed properly, stifling competition and becoming yet another taxpayer-funded money pit”.

Plaid Cymru supports the plan, but said it would scrutinise the legislation to make sure it delivers a better and cheaper service.

Plaid transport spokesperson, Peredur Owen Griffiths, said: “Bus franchising is a step that is integral to the future of sustainable, affordable and reliable bus services for the future, which makes the Labour government’s delay in its implementation frustrating. “

The government has proposed splitting Wales into regions, each introducing their own franchises over the next five years.

Franchising would start in 2027 in south-west Wales where First Cymru, one of the biggest bus companies, currently operates.

Its commercial director Rob Pymm said First would “fully embrace” franchising if the Welsh government goes ahead with it.

“We work really closely with all the authorities in Wales,” he added.

“We have got a really good relationship and we are feeding our decades of experience into their planning of that.

“Hopefully at the end of it we will be running those services as well.”

First Cymru runs the X6 service from Ammanford to Swansea city centre.

Rupika, 34, travels between Swansea, Neath and Bridged by bus for her work as a baker.

“It’s much, much cheaper than the train,” she said.

“When I come from Bridgend in the evening, the last bus I get is at six, but I feel it should be extended to eight because there are a lot of people who travel after that.”

Denver Gough, 67, of Trebanos, said the service was “pretty good” but “sometimes going back they’re not so reliable”.

He said putting the public sector in charge of the bus system made sense.

“I don’t think buses got any better from when they were de-nationalised to be honest with you,” he said.

“They cut the services. If you go back to the old days there were more buses than there are now, especially up in the valleys.”

Don Cornell, of Hafod in Swansea, said he used his bus pass nearly every day to do his shopping or get into town.

“It’s not reliable, I’ll tell you that now,” he said as he waited for his bus.

“Only one bus goes through the Hafod, the number six, so if that doesn’t turn up you’re waiting an hour – and most of the time it doesn’t turn up.”

Deborah Burr, 63, said she caught buses in the city several times a week.

“It’s difficult, you can’t blame the drivers because you’ve got roadworks and all the rest of it, and I understand that,” she said.

“But at the end of the day, I just want to go home or wherever it is I have to go.”