A UK Government minister has questioned why Scots will have to wait "a thousand more days" before the vote on independence is held.
Politicians at Westminster have repeatedly argued that the ballot on the country's constitutional future should be held sooner rather than later.
Chief Secretary to the Treasury Danny Alexander has challenged the Scottish Government's preferred date for the poll of autumn 2014.
Holyrood Finance Secretary John Swinney insisted that was now the "established date" for the historic vote to take place. But Mr Alexander questioned the Scottish National Party administration's timetable the day after First Minister Alex Salmond unveiled his referendum proposals to Holyrood.
Mr Salmond said he wanted to give voters a "short, straightforward and clear" choice by asking them: "Do you agree that Scotland should be an independent country?"
Both the Scottish and UK governments are now running consultations on the independence referendum.
Mr Alexander told BBC Radio Scotland's Good Morning Scotland: "I still think there's a question people will want to consider when they respond to these consultations about why it is we have to wait a thousand more days before we can get on and have this question asked."
The Scottish Government consultation published on Wednesday revealed its consultation would run until May 11. All responses then have to be analysed, with the the SNP administration due to introduce a Referendum Bill to Holyrood early next year. This could then be passed by October 2013, and gain Royal Assent the month after that.
The UK Government insists Holyrood does not have the legal authority to stage a ballot on independence, and has offered to temporarily extend its powers to allow a vote to take place.
The Scottish Government has rejected the "strings" Westminster has included in this, although Mr Salmond said on Wednesday he was willing to work with UK ministers to "ensure that the referendum is effectively beyond legal challenge".