John Mulvey, former leader of Lothian Region, believes a Yes vote in September is next logical step in Scotland's 'evolution of devolution'.
He said: 'I have gone from being a sceptic about the relevance of devolution given all the other major political issues of that time to being absolutely convinced that Scotland's future now lies with independence.'
Mr Mulvey's endorsement of Yes follows that of several other respected and powerful Labour figures. Sir Charles Gray, who was leader of Strathclyde Region around the same time - 1986-92; Alex Mosson, former Lord Provost of Glasgow, who was an 1980s council contemporary on Glasgow's Labour administration; and Lorna Binnie, chair of Falkirk Trades Council and leading trade unionist, have all declared support for Yes.
Mr Mulvey has been won over in part by the positive strides forward that have been made under a devolved government.
He said: 'A lot of people out there - former and current Labour supporters - are relatively happy with the Scottish Parliament and see that it can be even better than it currently is if it represented an independent country.'
Mr Mulvey was the boss of the No campaign's leader Alistair Darling in the early years of his political career. Mr Darling was a young councillor on Labour-controlled Lothian Regional Council back in the 1980s when Mr Mulvey was leader.
Mr Mulvey became Labour member for the region's biggest ward taking in Slateford and Wester Hailes, in 1978, became group leader on the authority in 1982, and council leader in 1986, a role he held for four years.
'I packed it in in 1990 because I was taken to court twice for refusing to pay my Poll Tax and they seized by bank account,' he recalled. 'It became a bit difficult to continue because I was opposing what would become the only source of revenue open to the council to fund its many and varied services.'
He led the council battle to fight the most hated tax visited upon post-war Scotland and to oppose plans to cut services.
'For a while we still had the power to raise rates but Malcolm Rifkind, who was then Secretary of State for Scotland, had to seek parliamentary powers to prevent us doing that,' he said.
His campaigning days did not end when he stepped down from the council, however. He has worked for various voluntary organisations, including anti-poverty campaigns. He was heavily involved in campaigning for the first bill in the Scottish Parliament for free school meals.
Mr Mulvey, 69, sees a Yes vote on September 18 as a road map for the future of Scotland.
He said:'I don't see it as me personally benefiting from independence at my age but I honestly believe it is for my grandchildren. It is an opportunity for them to live in a more egalitarian country that will have done away with nuclear weapons and living in a more green-related approach to the economy.
'First and foremost, this is a hugely important vote for the status of Scotland. There are those who don't support the SNP or, perhaps, don't like Alex Salmond. But it's more important than that. People of all political persuasions should come out and vote - preferably for Yes - and then decide what kind of Scotland they want to see in the election of 2016 when the political parties make their cases to be the first elected Government of the newly independent nation.'
Chairman of Yes Scotland Advisory Board Dennis Canavan said: 'I warmly welcome John Mulvey's declaration of support for Yes Scotland and I am sure that he will be a great asset to the campaign. I knew John as a Labour councillor in Edinburgh for many years and his experience as former leader of Lothian Regional Council gives him a very valuable insight into the governance of Scotland.'
Yes Scotland Chief Executive Blair Jenkins said: 'A man of John's knowledge and experience is a very welcome new voice in the campaign, particularly at this key time - the beginning of the Year of Yes.'
Sir Charles Gray has appealed to Labour supporters not to allow party allegiances to get in the way of making the right choice for Scotland in the referendum.
He said: 'A Yes vote will not only be good for Scotland - it will be good also for the Scottish Labour Party.
'And remember: a Yes vote means no more Tory governments at Westminster that we didn't vote for.'
Detailed research for Yes Scotland suggests that most traditional Labour voters are open to independence but many are held back from declaring their support because the party is officially opposed and is part of the Tory-led No campaign.