Reviews of electoral arrangements for the Scottish parliament and Welsh assembly are set to be launched.

The move comes as the government pushes forward legislation to reduce the number of Scottish seats in Westminster from 72 to 59.

Speaking in the Commons, Scottish secretary Alistair Darling said an independent commission would look at the impact of having non-coterminous boundaries for Holyrood and Westminster.

The boundaries are set to be changed in order to ensure that the number of MSPs does not fall when the number of Scots MPs is cut.

Darling said that under current plans there could soon be four different electoral systems in use north of the border.

"The commission will examine the consequences of having the four different systems in Scotland, and having different boundaries between Holyrood and Westminster," he said.

There will be consultations with other parties and cooperation with the Scottish executive, he added.

Coinciding with the announcement, Welsh secretary Peter Hain said he was prepared to consider a similar review for the Cardiff assembly.

“The electoral arrangements for the Scottish parliament are the same as for the Welsh assembly and clearly it makes sense to consider the option of a similar review for Wales," said Hain.

There have been complaints about the functioning of the list system in Wales, focused on the way in which candidates who fail to win constituencies can still be elected for the local region.

The independent Richard Commission is already reviewing the electoral system of the Welsh assembly, and Hain's decision on a further review is likely to come in the wake of those recommendations.

“Any government review I initiate needs to be informed by the assembly government’s response to the commission’s recommendations," the Welsh secretary said.

"Clearly we need to study that response before a final decision is made on whether I commission an additional review like that announced by the Secretary of State for Scotland today."