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Row breaks out between Reform and Plaid over Senedd election spending plans

Gareth LewisWales political editor
Getty Images On the left is Plaid Cymru leader Rhun ap Iorwerth. He's wearing a suit with an orange tie. There is a Plaid slogan in the background. On the right is Welsh Reform leader Dan Thomas. He's wearing a suit with a dark red tie and there are microphones facing in his direction. ReformUK is written on the mic stand.Getty Images
A row over the cost of Senedd election pledges has broken out between Plaid Cymru and Reform

A row over the cost of Senedd election pledges has broken out between the two parties who could be vying for the top spot in May.

Plaid Cymru has accused Reform of "uncosted pledges which would destroy public services", to which Reform has responded saying its rival used a "back-of-a-fag-packet calculation".

Reform has said it would lower income tax across all three tax bands, cap council tax rises and build an M4 relief road around Newport if it comes into power.

Taxation has featured in all the manifestos published so far, with the Welsh Conservatives pledging to knock a penny off the basic rate of income tax and Labour saying it will not put up Welsh rates of income tax.

BBC Wales has been told that the costings have been analysed by independent think tank the Institute for Fiscal Studies (IFS), but despite a number of requests, the costings have not yet been published.

Plaid Cymru and the Greens are expected to unveil their manifestos this week, with the Liberal Democrats due next week.

Reform's Welsh leader Dan Thomas has also repeated a promise, made a month ago by Nigel Farage, to publish the party's costings, despite initially saying the details would not be released.

Polls suggest that Plaid and Reform are battling it out to be biggest party, with Labour facing a fight to hold on to power.

Plaid claimed that Reform's plans to cut income tax, cap council tax rises at 5% and build an M4 relief road would lead to a £1bn black hole in Wales' public finances.

In a statement, it said capping council tax would lead to a £437m shortfall for local councils and that an M4 relief road could cost around £492m a year over a five-year construction period.

The BBC has already reported that Reform's plans for income tax would cost about £371m in the current financial year.

Getty Images Plaid economy spokespersons Luke Fletcher wearing a suit. It is a head and shoulders shot and he is stood in front of an orange background.Getty Images
Plaid's Luke Fletcher says Reform's mainfesto amounted to "fantasy economics"

Plaid's economy spokesperson Luke Fletcher said Reform's manifesto sums "simply don't add up", and called their strategy a "gamble" rather than a plan.

"It's fantasy economics with no costings."

Fletcher also accused Reform of having a "hidden austerity agenda" which would "destroy" public services.

In response, Reform's Welsh leader Dan Thomas said Plaid "did not have a leg to stand on when it comes to sums".

"They won't even show their working for this back-of-a-fag-packet calculation," he added.

Plaid has not published its exact calculations.

Thomas also challenged the party to publish its manifesto costings when it unveils its plans this week.

Getty Images Dan Thomas and Nigel Farage standing front of a Reform UK logo. Farage has one hand in the air waving to people.Getty Images
Dan Thomas was appointed by Nigel Farage in February to lead the party into the Senedd election

Labour pledged to not raise Welsh rates of income tax in its manifesto launch last week and also said it would make council tax "fairer".

Welsh Labour leader Eluned Morgan told BBC Wales that the party was still committed to council tax reevaluation by 2028.

The Welsh Conservatives said they would take a penny of the basic rate of income tax, cap council tax rises at 5% and would also build an M4 relief road.

Although it is yet to publish its full set of plans, Plaid has faced questions of its own over its decision to expand childcare to cover all children from nine months to four years old, costing between £400-£500m a year by the end of a five-year rollout.

The party's opponents have challenged Plaid to spell out what services it would cut to pay for the policy.

Plaid leader Rhun ap Iorwerth said "we know it is money we can afford" when the plans were announced in October 2025.

Wales Green Party and Liberal Democrats are also yet to publish their manifestos, but have suggested they would replace council tax and - if necessary - put a penny on income tax to pay for social care respectively.

The IFS has warned that Reform's plans do not fully "face up" to tax and spending realities for the next Welsh government.

It also said that the Welsh Conservatives' plans could lead to significant cutbacks to public services and that Labour's income tax plans could leave it little room to manoeuvre.

Wales goes to the polls on 7 May under a new system of proportional representation, which should more accurately reward parties for the percentage of the vote that they win.

The Senedd is expanding from 60 to 96 seats and will have 16 new constituencies, each returning six Senedd members.

No party is expected to win a majority, which means that there could be a period of negotiation to strike a deal to govern.

Votes will be counted on 8 May.

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