The Scottish National Party's white paper Scotland's Future - Your Guide to an Independent Scotland has been described as the point "where the independence argument properly began."

It has certainly unleashed unprecedented engagement in the debate, with more than 36,000 free copies being distributed to an interested public.

The white paper sets out a vision of independence that represents a significant advance for Scotland in my view - affording us the right to self-determination and the chance to build the type of nation we want.

There is much in its 700 pages to commend it, such as the commitment to a written constitution enshrining certain agreed rights for the people, removing Trident nuclear weapons from our soil and seas, and boosting Scotland's economy and population by welcoming those who wish to come and live here.

It also pledges to return Royal Mail to public hands, scrap the hated bedroom tax, provide universal free childcare for pre-school children, give seats on company boards to workers, support greater environmental protection, extend much-needed social protection to vulnerable and disadvantaged groups and reduce gas and electricity bills by 5 per cent a year.

The contrast with the consequences of a No vote next year could hardly be starker. More Tory governments we didn't vote for, more Trident nuclear missiles stationed on the Clyde, further falls in the living standards of the working-class majority and increasing inequality and deprivation.

Having said that, there is more that could and should have been included in the paper.

Given the exorbitant cost of heating I would have liked to see the Scottish government go further on gas and electricity bills. It could, for example, have reiterated its 2007 manifesto pledge to eradicate fuel poverty in Scotland altogether.

It could have pledged to take the energy industry in Scotland into public ownership, just as it did recently with Prestwick airport.

It should also have included a promise to repeal the worst anti-trade union laws in Europe - a move that would undoubtedly have been welcomed by the country's 630,000 trade unionists and their families, especially in the aftermath of the recent Grangemouth dispute.

Each of these measures would have complemented the strong social-democratic tradition the independence case promotes.

Such commitments would persuade more working-class people to vote Yes next year.

Last week's Panelbase opinion poll showed a 9 per cent lead for the No campaign, but also revealed that its support was highest among better-off social classes, while support for the Yes campaign was higher among the poorest.

And the latter also register the highest proportion of "don't knows." If the independence movement in Scotland is to win greater working-class support we need to provide them with better reasons to vote Yes than we have done so far.

Left-wing organisations that support independence such as the Scottish Socialist Party have a crucial role to play in persuading working-class voters who are justly sceptical of the sort of change Alex Salmond and the SNP have in mind that they would still be better off with independence.

That's why our response to the white paper is that other visions of independence are available.

We believe that independence could bring immense benefits to Scotland - but we advocate an independent socialist Scotland and, like many Scots, we favour a modern democratic republic.

There are inevitably some proposals in the white paper which should not receive support. Commentator Ian McWhirter identified these as presenting "a rather unionist vision that seemed above all to celebrate the BBC, the monarchy, Nato, the pound, the Bank of England and the British passport."

We shouldn't back a reduction in corporation tax for Scottish businesses by 3p or entry into a "sterling zone" which hands control of monetary and fiscal power to the Bank of England.

We ought not to support maintaining Nato membership or retaining an unelected, unrepresentative feudal monarch as our head of state.

But as a democrat I can accept the white paper's argument that "decisions about Scotland will be taken by the people who care most about Scotland - those who live and work here."

And in that spirit I acknowledge that all the specific policy issues in the paper should and would be decided by the people of Scotland in the first elections to an independent parliament in 2016.

Colin Fox is joint national spokesman for the Scottish Socialist Party and sits on the Yes Scotland advisory board