Peter Hain has two roles as Welsh secretary and Commons leader

Peter Hain is using a constitutional lecture in London later to question the system under which one third of the 60 AMs are elected.

He says it is wrong that would-be AMs are able to stand and lose in individual constituencies, only to re-emerge as elected AMs under the list system.

He said: "At a very minimum, candidates should have to choose between standing in a constituency and standing on the regional lists.

"Doubtless many will question whether list AMs should have smaller staffing and expense allowances than constituency AMs who have to serve their constituents," he added.

Mr Hain explained how in Clwyd West last year, three of the defeated candidates were elected on the North Wales list, including AM Eleanor Burnham, who won just 7.9% of the vote.

He said the winners, despite losing in the constituencies, are then able to set themselves up in competition with the constituency AM.

Lord Richard is heading an inquiry into the assembly's powers

But Jonathan Morgan, South Wales Central AM, said regional AMs cover eight standard constituencies, and so were likely to have an increased workload.

"This is classic hypocrisy from Peter Hain about a Labour-created system," he said.

"All 20 regional seats in Wales are now occupied by opposition parties, so it doesn't take a genius to work out why Peter Hain wants to create a two tier system.

"I wonder why we never heard this sort of winging last term when Labour held a regional seat?"

Elsewhere in the lecture, Mr Hain will look at various options for the future of the Welsh assembly.

These include a Northern Ireland-style assembly, with AMs given the power to make laws in areas already run from Cardiff Bay.

But he said the Richard Commission, which is currently considering the assembly's powers, should look at what practical benefits a change in powers would mean to the people of Wales in terms of jobs, improved health care, education and transport.