Image caption Nathan Gill MEP said the Barnett formula has a 'lot of unfairness within it'

UKIP is pledging to change the spending formula used by the UK Treasury to determine the Welsh government's budget if it gets into power.

The party says it will "radically reform" the Barnett formula so that finances to the devolved governments are calculated on the basis of need rather than population.

MEP Nathan Gill said the intention is to increase payments to Wales.

Critics say Wales is short-changed by the funding mechanism.

In 2009, an independent Welsh government-appointed commission estimated the annual shortfall was around £300m.

Although some, including the author of the review, have suggested the current figure is lower.

Prime Minister David Cameron, Labour leader Ed Miliband and Liberal Democrat leader Nick Clegg vowed to keep the Barnett formula in the lead up to the Scottish independence referendum.

Public spending

UKIP Wales leader Mr Gill said the party's election manifesto would include a pledge to change the formula, which they believe unfairly favours Scotland.

He told the Sunday Politics Wales programme: "It does have a lot of unfairness within it.

"For Scotland, we will definitely be addressing this. We will reduce the amount of money that the Scots receive through the Barnett formula.

"But within Wales we have no intention of removing the Barnett formula; in fact our intention is to increase the payments that Wales will receive."

A recently published Treasury document showed that public spending per head was highest in Northern Ireland (£10,961), followed by Scotland (£10,275), Wales (£9,924) and England (£8,678).

The latest devolution package, announced by Mr Cameron and Mr Clegg, included a guaranteed level of minimum funding for the Welsh government through the formula.

Funding gap

Welsh Secretary Stephen Crabb has previously denied Wales is underfunded by the UK government, saying it enjoys "a substantial subsidy".

Shadow Welsh Secretary Owen Smith has said a UK Labour government would look to close the gap in Wales' funding by adopting a "Barnett plus" formula.

Plaid Cymru said they would demand Wales gets the same funding deal as Scotland in a hung parliament - a move they say would boost Welsh finances by £1.2bn.

The Liberal Democrats have made a "pre-manifesto" pledge to give Wales top-up payments to plug the funding gap.

Sunday Politics Wales, BBC One Wales, 11:00 BST.