Labour has not had a good week in the wake of the Scottish independence referendum row, a UK Government minister has admitted.
But Scotland Office minister David Cairns insisted the party was united in its stance against the SNP.
Scottish Labour leader Wendy Alexander called on Scottish ministers to bring forward its 2010 referendum plans.
Prime Minister Gordon Brown pledged to do "whatever is necessary" to preserve the United Kingdom.
But, in an interview with the Sunday Telegraph newspaper, Mr Brown gave his backing to Ms Alexander, describing her as an "excellent leader" of Labour in Scotland.
Ms Alexander also repeatedly denied stating in an earlier BBC interview Mr Brown had specifically endorsed her move to call for the early referendum.
A week after Ms Alexander's comments, Mr Cairns told BBC Scotland's Politics Show: "This hasn't been a good week for us and my thoughts are with the hundreds of thousands, of not millions, of Labour voters who are wondering what on earth is going on."
But he added: "In the end, what matters is, can we as a Labour party look to our supporters and say, 'do we have your best interests at heart? Do we have the best interests of Scotland at heart? Do we all believe Scotland is better in partnership with our friends and our colleagues and our relatives in England and Wales and Northern Ireland.'
"Everyone in the Labour party believes that with a passion."
Mr Brown, who failed to explicitly support Ms Alexander's position in the Commons, stressed he was personally "not persuaded" of the case for a poll.
Also speaking on the programme, Ms Alexander again denied trying to bounce the prime minister into backing her position, and insisted she had his support in pursuing whatever tactics were right in the Scottish Parliament.
And when repeatedly challenged over why she told the BBC's Newsnight Scotland that Mr Brown endorsed her referendum call, Ms Alexander replied: "The prime minister has endorsed my right as leader of Labour in the Scottish Parliament to do whatever we think it takes to expose the hollowness of the SNP."
Douglas Alexander said he was not contemplating a referendum
Mr Brown said: "I will do anything and everything to ensure that the case for the Union, which has served Britain and the British people so well, is properly heard and advanced."
The prime minister went on: "I want all unionist parties and all parts of business - employers, managers and trade unions - to work together not only to push the case for the Union but to expose the dangers of separation.
"Some issues are bigger than politics and need to be addressed in the common interest."
International Development Secretary Douglas Alexander, one of Gordon Brown's closest allies and Ms Alexander's brother, told the BBC's Andrew Marr programme he did not believe now was the right time for a referendum.
He added: "The SNP were elected under a manifesto of having a referendum, but they've made very clear in their response to what Wendy's said this week that they have no intention of bringing forward a referendum until they've fermented more grudge and grievance."
Scottish deputy first minister Nicola Sturgeon said: "This has been a disastrous Grand Old Duke of York double act - Wendy marches Labour to the top of the hill and Gordon Brown orders her down again.
"Wendy Alexander has been caught out clearly misleading the people of Scotland. She was visibly squirming when effectively conceding that she misled the people of Scotland on Newsnight about the position of Gordon Brown on a referendum."