Plaid demands more cash, but how could the Budget affect Wales?
Welsh Finance Minister Elin Jones has called for a spending plan that "finally treats us fairly".

Plaid calls for more funding, but what impact could the Budget have on Wales?
Plaid Cymru ministers say they want extra money for railways and public services in Wales before the UK government's Budget on Wednesday.
Welsh Finance Minister Elin Jones urged Chancellor John Healey to present a spending plan that "finally treats us fairly".
The Budget sets out Westminster's tax and spending plans for the year ahead - and extra money for English public services could lead to additional spending in Wales, where those services are devolved.
A UK government spokesperson said the chancellor would concentrate on giving households and businesses "a bit of breathing space where we can".
Meanwhile, shoppers in one of Wales' busiest markets told BBC Wales that the cost of living was once again their main concern ahead of the spending announcement.
Any extra spending on services in England that are controlled in Wales by the Welsh government - such as healthcare, schools and roads - could trigger more money for the country.
Elin Jones asked the chancellor to advance £1bn of the £14bn the UK Labour government had promised for long-term rail funding in Wales.
She also requested extra funding to help the Welsh government balance its budget for 2027-28, which is currently facing a real-terms cut in day-to-day spending.
She had previously said Wednesday's settlement could be the worst for the Welsh government since the Covid-19 pandemic.
Jones said Wales had been short-changed "for years".
"This UK Budget is the moment of truth, and we need the chancellor to act, not just acknowledge the problem," she said.
"Wales pulls its weight in the UK economy. We contribute. Now we need the UK government to match that ambition with action and deliver a budget that finally treats us fairly."
There have also been calls from Labour MP Nia Griffith for the Welsh government to be given more freedom to borrow for investment projects.
A senior Welsh Labour source said they had been "pressing really hard for fiscal flexibility", along the lines of Griffith's request.
Before Wednesday's announcement, shoppers and traders at Swansea Market said the cost of living was their biggest worry.
"Will we be able to see through the winter without having to borrow money," said shopper Louise. "It's quite a worry."
Like others at the market, Louise said she felt "anxious" about the winter, even though she had saved some money with her supplier.
Support with energy costs was at the top of many people's wish lists for the Budget.
Prices rose at the start of the month and typical bills are expected to rise by 16% in January because of the conflict in the Middle East.
Louise says she is worried about the winter because "everything is getting more expensive"
Father-of-two Richard said his pay had not kept pace with rising energy bills, leaving his family "penny pinching towards the end of the month".
"Things that we used to have as a bit of luxury are out of the question, days out with family cost a fortune," he said.
Rural homes that rely on heating oil have also seen costs rise sharply. The chancellor had already announced he will remove import taxes to bring the price down slightly.
Healey has spoken about giving people "breathing space" from cost-of-living pressures, and has unveiled a package of small measures he is calling "everyday fixes" ahead of the Budget.
Prime Minister Andy Burnham also wants to reduce standing charges on gas bills.
If more support is announced in the Budget, it is likely to be limited and targeted at the poorest households.
Richard, from Swansea, says "a lot of things that used to be affordable are now out of reach"
The cost of filling up cars surged this year as the conflict in the Middle East pushed up oil prices.
Petrol prices reached a four-year high in September, and diesel has also risen sharply.
The cost of transporting fruit and vegetables is one problem putting pressure on Gareth Evans, the fourth generation of his family to run the Get Fresh stall at Swansea Market.
"It's a struggle at the moment," he said.
"We get costs passed on to us from our suppliers.
"We've also got vans ourselves and we supply caterers and diesel is very expensive."
Emma, who runs a pet store, said her rising costs have forced her to raise prices for customers, as "it goes down the line".
She believes many working people are "struggling to live now".
The chancellor is expected to freeze the planned rise in fuel duty in January.
The rate was cut by 5p by the previous Conservative government in 2022 and that measure has already been extended twice.
Gareth took over the family fruit and veg stall from his father Chris, who had worked there for 50 years
One of Elin Jones' requests is for UK government support for a flagship scheme aimed at tackling child poverty.
The Welsh government is planning a trial scheme that will pay 15,000 children in families on universal credit £10 a week.
Welsh ministers have asked the UK government to exempt the payments from tax and benefits calculations, so recipients do not see their income reduced.
BBC Wales has been told talks about the child payment are still continuing, suggesting there will be no announcement on Wednesday.
Burnham had previously said he was "open" to considering this, and it has already been granted to help the scheme in Scotland.
The chancellor will also announce how much the state pension will rise next year.
It appears likely to exceed £13,000 a year, with the full flat rate expected to rise by £488 a year in April because of the triple lock guarantee.
One measure already announced is that pensioners who rely entirely on the state pension will be protected from paying income tax, which usually starts at £12,570.
The exact details will be set out in the Budget.
On working-age welfare, Healey has been preparing Labour MPs for possible cuts to the benefits bill, with a carefully scripted speech at this year's party conference.
There are reports that young people not in education, work or training may face major changes to their support, but that could be announced after the Budget when former Health Secretary Alan Milburn publishes his recommendations for reform.
Reform UK Senedd member Cai Parry Jones said his party "would stop using Welsh people as cash cows", and would build an M4 relief road, scrap family farm tax, and "reward working people" by raising the tax-free personal allowance to £15,000.
Welsh Conservative Senedd leader Darren Millar called on the UK government to provide money for major road projects, including an M4 relief road, and more defence spending in Wales, calling for a "pro-union Budget deal".
David Chadwick, Welsh Liberal Democrat MP, said his party wanted a Budget that gave Welsh families "some much-needed breathing space", calling for a 10p cut in fuel duty, a guarantee to bring down energy bills, and a temporary VAT cut for hospitality.
The Budget comes before the first substantive meeting between the prime minister and the first minister at the National Economic Council later this week, where devolution is expected to be discussed.
A UK government spokesperson said: "The chancellor is focused on giving households and businesses a bit of breathing space where we can. That's why we have removed VAT from electricity bills, extended the 5p fuel duty cut and frozen rail fares."

