Referendums on directly-elected assemblies in two English regions have been ruled out for at least six months, the Government said today.

Planned November polls on devolution in the North West and Yorkshire and the Humber were postponed earlier this year amid fears over the security and efficiency of all-postal voting.

Local Government Minister Nick Raynsford announced that a decision on an alternative system would be put off at least until experts report in March.

The latest delay comes after the Electoral Commission reversed its backing of all-postal voting following problems with large-scale pilots at June's European and council elections.

Giving MPs a promised update on the situation, Mr Raynsford insisted the Government was "absolutely committed to the referendums going ahead and would aim to "minimise the delay".

And he said the commission had recommended that all-postal voting should still be used for a referendum in the North East, which is still going ahead in November.

The Tories said the experiment with all-postal voting had been a failure and called for the poll in the North East to be called off as well.

Mr Raynsford said the commission had concluded that all-postal voting had delivered "successful elections" in June with no evidence of "widespread abuse".

However, the trials raised "a number of important issues", including the fact that the system did not offer the choice of polling methods that voters wanted.

"Accordingly, the commission has withdrawn its previous recommendation that all-postal voting should become the norm in local government elections," he said. "We share the commission's belief as to the importance of securing a degree of public and political consensus for significant changes to the electoral process before moving forward.

"Against that background it would be wrong now to reach final conclusions on the precise timing and form of the referendums in the North West and Yorkshire and the Humber.

"Over the coming months we, and others, will want to see how work progresses on the new foundation model and to consider and analyse more deeply the full range of the commission's recommendations."

The Minister added: "I would however reiterate what I said in July - the Government is absolutely committed to these referendums going ahead."

He concluded: "The extensive electoral pilots last June have much to teach us all.

"But the way is now clear for the people of the North East to make their choice on an elected assembly for their region.

"And the people of the North West and Yorkshire and the Humber can be confident that they too will be able to exercise their choice before too long."

Pro-devolution MP Ann Cryer, who represents Keighley, urged ministers to press ahead with a referendum.

She said concerns about electoral fraud were overblown because people would be voting for an idea, not a person as in other elections.

Mrs Cryer said: "I think you could quite safely have a postal vote in a referendum for a regional assembly.

"Council and General Elections are about personalities, so in certain areas people are coerced to vote for their extended families or friends.

"You would not get that in a referendum, so I would not worry a jot about fraud."