Energy secretary Ed Davey has previously warned that English and Welsh energy consumers should not be expected to subsidise Scottish energy if cheaper alternatives can be imported from other countries.
Later in the day shadow minister Caroline Flint added that a Labour government after the next general election would take the same stance.
At a conference hosted by business lobby group CBI Davey argued that a change in the relationship between an independent Scotland and the remainder of the UK is inevitable if Scottish First Minister Alex Salmond insists on having a separate Scottish energy regulator and its own secretary of state.
“There’d bound to be divergence,” Davey said, adding that the UK may “might decide is quite expensive” and opt for imports from other countries.
Flint echoed the warning, saying: “You can’t have your cake and eat it, I’m afraid.”
“ will look for the best deal we can get – that might be Scottish, but it might not be,” she added.
In a Q&A session Davey was asked why, even without a yes-vote to independence, the UK should subsidise Scotland’s ‘quite expensive’ renewable generation if cheaper imports are available.
He told the conference that the cost of subsidising network connection to remote Scottish islands and highlands would add £38/year to a Scottish consumer bill, before the renewable electricity had been subsidised, but that “smoothed” over a larger UK consumer base it would be far less.
“ would not be to the benefit of the Scottish people,” he said.
Flint added later that there are “great strengths” from the ability to share the strengths of a union and divide the risks.
“We gain so much more from being together – I hope Scots will vote no,” she said.