Leaders' vow to Scotland could cost Wales

'The Vow,' a series of pledges set out jointly by David Cameron, Ed Miliband and Nick Clegg, has been described both as a panic move by out-of-touch leaders and a sincere promise of more powers for Scotland if it remains part of the UK.

Amongst the promises is a commitment to retain the way that UK Government public spending is divided between the different nations, known as the Barnett Formula.

There's widespread agreement amongst political parties in Wales and most commentators that the formula is more generous to Scotland.

A generally accepted estimate is that Wales loses out by around £300m a year while Scotland gains by about £4 billion a year.

The First Minister Carwyn Jones has repeatedly said that 'fair funding' is a priority for his government and that he'd refuse any move to impose income tax powers that unless the Barnett method of working out how to share out spending is replaced with a 'needs-based formula.'

Labour's opponents say that the commitment to keep the formula in place if Scotland votes 'no' proves that the party doesn't care about Wales' needs.

Plaid Cymru's leader Leanne Wood said.

When asked what a future Labour government would do about the funding formula, Ed Miliband and Ed Balls have both repeatedly acknowledged that they recognise there's an 'issue' with Wales' allocation and would aim to put that right.

Welsh Labour sources have underlined that pledge today in response to the party leaders' fresh commitment to the current arrangements and have ridiculed Plaid Cymru's 'obsession with Barnett.'

Promising Scotland continuing high levels of funding, they tell me, doesn't mean not sorting out Wales' underfunding.

But not everyone in the party agrees. Delyth Evans, a former Assembly Member who's Labour's Parliamentary Candidate in Carmarthen West and South Pembrokeshire for the party tweeted: