The referendum on independence will be the most important political decision Scotland makes, Scottish Secretary Michael Moore has said.

But the UK Government minister said he was confident that voters would make the "right choice" when the poll is held.

Mr Moore said the issue of the referendum, for which no date has yet been announced by the Scottish Government, "looms large" following the SNP's historic majority win in the Holyrood election.

The outcome of the 2011 election, he said, meant "all of us across Scotland will soon need to decide where we stand on staying in the UK or becoming a separate country".

The Liberal Democrat politician added: "It will be the most important political decision that the Scottish people will ever make."

While he said he was "confident that people will listen to the arguments and make the right choice", Mr Moore stressed the need for an "open and frank debate" on Scotland's constitutional future.

He also used his New Year message to urge those in favour of Scotland remaining part of the UK to speak out during 2012.

Mr Moore said the issue of whether or not Scotland should become independent was "too important — and potentially irreversible — a subject for silence".

"We saw a number of strong opinions and arguments in favour of Scotland's place in the UK this year, but I know many others hold similar views," he said.

"Next year is the time to air them and choose to enter the debate: at stake is Scotland's place in the world and our future prosperity."

He also argued there was a need for "clarity in the next few months" on some of the details of the referendum, saying: "As it stands we might have a referendum in 2014, 2015 or 2016. There is talk of multiple questions, different options and creating a whole new body to run the poll.

"It's only fair for people in Scotland to be able to understand the plan."

The Scottish Secretary said it was "right that there now should be a referendum" but added: "Equally, the Scottish people have the right to expect a referendum that is legal, fair and decisive. There are still many questions for the Scottish Government to answer."

A spokesperson for Bruce Crawford, Cabinet Secretary for Parliamentary Business and Government Strategy, said: “We welcome the fact the Scottish Secretary accepts that the people of Scotland have the right to choose their own future, and the referendum is clearly a matter for the Scottish Parliament and Government.

"We will stick to the pledge we made in the election campaign to hold a referendum in the second half of this five-year parliamentary term – a pledge that was overwhelmingly endorsed by the people in that election.

“In terms of the referendum itself, it will be run to the very highest international standards, meeting the gold standard in terms of transparency and rules.”