Scottish Secretary Michael Moore has said that he was "more confident than ever" on reaching a deal with nationalists over an independence referendum.
After a third round of negotiations with the Scottish National Party on Tuesday, Liberal Democrat Mr Moore said there was "goodwill on both sides" over the issue. Officials and lawyers have been asked to draw up a possible package for further discussion, he said.
Speaking at the Lib Dem autumn conference in Brighton, he stressed that a referendum run from the Scottish Parliament could only happen with the agreement of the Westminster Government.
He has previously stated that that consent will only be given if there is just one question on independence - and no second question on further devolution.
"Yesterday I met with the Deputy First Minister (Nicola Sturgeon) for a third round of negotiations and I am more confident than ever that we can reach that agreement," he said.
"I believe that there is goodwill on both sides. We've discussed all the substantive issues, so we're moving on to the crucial detail. And we have now asked officials and lawyers to put pen to paper so that we can both see in print what a package might look like. We'll talk again. But we would not be talking at all if we did not believe that an agreement could be reached. That we can find a way to put this crucial question to the Scottish people."
Mr Moore insisted that Lib Dems in the UK Government were delivering benefits for Scotland and that independence would spell insecurity.
"When we go to the polls in 2015, we won't head into battle armed only with words. We have an armoury of evidence and a record of delivery," he said. "We have shown that even in the toughest of times, and against all the odds, Liberal Democrats have done for Scotland what Labour did not and the Conservatives would not."
He said Scotland should stick with devolution rather than independence, adding: "Scots making decisions closer to those they affect while remaining secure within a strong and stable UK. It means the best of both worlds for Scotland."
Lib Dem leader in Scotland Willie Rennie urged activists from across the UK to make their voices heard over independence and not allow the debate to be dominated by "extreme" nationalist voices. He told the conference: "I want the moderate, reasonable, open and welcoming voices from outside Scotland to be heard. Whatever you value I want you to make your voice heard. Promise me you won't leave the debate to the extreme views of nationalists."