Scotland should control two-fifths of its own revenues with the power to raise taxes on the rich, according to Labour.
The party has unveiled the long-awaited findings of its Devolution Commission in Edinburgh.
The Scottish Parliament should raise around 40% of its own revenues, around £2 billion more than the most recent Scotland Act.
The Scotland Act will give Holyrood control over more tax raising powers in exchange for a 10p in the pound cut in the block grant, but Labour believes this should be extended to 15p - giving Scotland control of three quarters of the basic rate of income tax.
The leader of the Better Together campaign and former Labour Chancellor Alistair Darling said he was offering a "positive vision" for staying the UK.
On the day of the six-month countdown to the referendum, Mr Darling added that independence would bring "huge risks".
"What the last few weeks have shown is that leaving the UK would create huge risks and cost jobs in Scotland.
"On what would replace the Pound, how our pensions would be paid and what would happen to our membership of the EU, leaving the UK would be a big leap in the dark.
"This is what Scotland's largest employers are saying. From Standard Life to Shell, and from RBS to the shipyard owners on the Clyde, walking away from the UK means people in Scotland would lose their job. That's the price of independence. It's a risk that we simply don't have to take."
– Leader Better Together Campaign Alistair Darling
The Scottish Deputy First Minister Nicola Sturgeon has set out what she claims are six "compelling reasons" in favour of independence to mark the milestone that it's six months to the Scottish Referendum.
She argues an independent Scotland would create more jobs, spend tax revenues on "Scotland's priorities", protect public services, "guarantee we get governments we vote for", set up an oil fund and have a retirement age in line with Scotland's circumstances.
"The referendum is a choice between taking Scotland's future into Scotland's hands or leaving our future in the hands of an out-of-touch Westminster establishment.
"The No campaign call themselves Project Fear but we have seen a move to Project Threat in recent days with increasingly over-the-top comments.
"So it's no wonder that support for Yes continues to advance in the polls while the No campaign has stalled - with a swing of only around 5% now needed to secure a Yes vote in September."
People in the Scottish Borders and Dumfries and Galloway will join fellow Scots in six months time to vote in the Scottish Independence Referendum.
Senior politicians and campaigners from both sides of the argument are holding events and debates in Scotland to look ahead to September 18.
Nationalists say the momentum is with the Yes campaign with half a year to go, but those who want to keep the union have warned that there will be no going back if Scotland crosses the line to independence.
Prime Minister David Cameron will address the Scottish Conservative Party conference being held this week at the Edinburgh International Conference Centre. The referendum on Scottish independence is expected to be high on his agenda.