The Coalition is "close to agreement" with Scotland's First Minister Alex Salmond on the terms of an independence referendum, it will announce today.
The Government will drop its demand for an early vote, allowing the Scottish National Party to delay the plebiscite until 2014. But in return, the SNP would have to agree to a single "yes or no" question on the ballot paper, dropping the so-called "devo max" option of further devolution short of full independence.
Michael Moore, the Scottish Secretary, will today warn the SNP that pressing ahead without approval would almost certainly result in a legal challenge on the grounds that the Scottish Government does not have the power to call a vote.
Mr Salmond is expected to announce his referendum plans shortly. The "devo max" option is seen as an insurance policy for the SNP in case full independence is rejected, as the latest opinion polls suggest.