The UK Government's U-Turn over the timing of the independence referendum has dealt a "serious blow" to the pro-Union campaign's credibility, according to an SNP MP.
Scottish Secretary Michael Moore said in a BBC interview that the UK Government did not see the timing of the poll "as a barrier to getting agreement on the referendum".
The Liberal Democrat's comments echoed those of Prime Minister David Cameron, who earlier in May stated that he was "not fussed" over the timing of the vote, despite previously having called for it to be held sooner than the SNP's preferred autumn 2014 date.
SNP campaign director Angus Robertson MP said: "After a year of huffing and puffing and trying to dictate the timescale of Scotland's referendum from Westminster, Mr Moore and the anti-independence parties have collapsed in a heap over the date.
"It is a very welcome step forward, but begs the question of why they spent such a long time making a fuss about something that even the Prime Minister says he is 'not fussed' about.
Mr Robertson pointed out that the Electoral Commission had drawn "particular attention" to the need to allow proper time to prepare for the referendum.
He added: "Having lost on the process, this is a serious blow to the credibility of the No campaign in terms of the substance of the debate on Scotland's future."
Mr Moore's comments came during an interview on BBC programme Sunday Politics, where he also announced that the formal campaign against independence will begin soon.
Michael Moore said those in favour of keeping the Union were "already engaged in the debate" and insisted there was plenty of time for all the arguments to be aired.
He said: "We will see the cross-party group launched before too long, but already significant voices like that of the former chancellor Alistair Darling are out as part of that campaign. We have a while to go; there will be plenty of time for all the detail of the debate to be worked through."
He said the campaign to keep the Union would feature people from different political parties and would involve people from all walks of life.
"I thought it was quite significant that this week we saw precious little of the business community supporting the independence campaign," he said.
Mr Moore also told the show: "We've got the biggest decision in 300 years facing all of us who live here in Scotland. I think that this will basically come down to a simple proposition - that we are stronger as part of the United Kingdom and weaker apart."
The launch of the pro-independence Yes Scotland campaign on Friday saw famous faces such as actors Brian Cox and Alan Cumming team up with politicians including First Minister Alex Salmond.
Supporters at the event, staged in an Edinburgh cinema, signed a "Yes declaration" stating it is "fundamentally better" if decisions about the country's future are taken by the people of Scotland.
The campaign aims to get 1,000,000 voters to sign the declaration before the referendum.
- UK and Scottish governments 'closer to agreement on referendum'
- Scotland Tonight: Referendum consultation
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