Jon Owen Jones criticised the plans

The bill, which contains the assembly's key Welsh NHS reform plans, is facing a rough passage through parliament on its first reading, with the Liberal Democrats refusing to back it in its entirety..

The pair were among a group of Labour MPs who met Ms Hutt on Monday night in an attempt to persuade her to change her mind.

Mr Griffiths, who oversaw health in Wales until 1998, said the new boards would be too small to be viable and should be based on NHS Trust lines.

He told BBC Wales there should, instead, be around 12 regional boards, with some having control of two local authority regions.

"I'll be putting an argument to her about why we need fewer than 22," he said.

"We need to take a deep breath and say we've got the principle right - matching local government units with health service units.

"But do we need to base it on the 22 government units or do we go with the health units or do we go with a combination of the two?

"We are going to need some really skilled and talented people to run them and it would ease the burden if we had a dozen or so."

Win Griffiths said 12 boards were sufficient

But Plaid Cymru members at the Welsh Assembly expressed frustration that the plans were being scrutinised in Westminster but not Cardiff.

Jane Hutt's plans were met with criticism when they were announced last week, but the health minister said she had the backing of community health councils.

Politicians in Westminster are debating the 70-odd clauses in the Bill, of which around 10 relate to Wales.

But, speaking in the assembly on Monday, Plaid leader Ieuan Wyn Jones questioned why the MPs had six and a half hours to scrutinise the plans "while the assembly haven't had a single minute's debate on it so far."

He claimed Labour MPs Mr Jones and Mr Griffiths were going to "going to tear lumps" out of the assembly's plans in the Commons.

Jon Owen Jones, who controlled health in Wales before the Welsh Assembly's inception, told Liberal Democrat health spokesman Evan Harris - who opposes the bill - the Welsh plans would fall if the bill was not supported.

is said to be angry MPs have only just received the assembly's consultation document on the issue.

The assembly is to debate the bill's Welsh clauses next week.