The blueprint, recommended by the Scottish Constitutional Convention's executive committee and expected to be endorsed by the full convention on Friday, would give the new legislature wide powers over a range of domestic affairs, including education, training, health, local government, home and legal affairs and industry.
Speaking at a joint press conference with Jim Wallace, leader of the Scottish Liberal Democrats, George Robertson, Labour's spokesman on Scottish affairs, declared that the parliament would make a "huge difference to the lives of ordinary Scots ... [it] will bring democracy back to Scotland".
The convention includes representatives from Labour, the Liberal Democrats, the churches and the trade unions, but has been boycotted throughout by the Scottish National Party and the Conservatives.
The 129-member parliament would be elected by proportional representation with an electoral agreement to ensure equal representation of men and women.
Mr Wallace, whose party is committed to reforming the voting system for the Commons, said: "The parliament is to be fairly elected, so that no single party or region will be able to dominate."
The Tories and the SNP attacked the plan, for different reasons. Michael Forsyth, Secretary of State for Scotland, said it was dangerous, irresponsible and would encourage separatism. The SNP, which wants an independent Scotland, called it a constitutional mouse which a future Westminster government could abolish with the stroke of a legislative pen.
It is not possible to expressly guarantee the continued existence of the parliament because the UK has no written constitution. Yesterday's blueprint seeks to secure the parliament's existence and powers through a declaration of the UK Parliament before the debate on the Bill setting it up.
The parliament would be Scotland's first since the early 1700s and would have the power to vary income tax by 3p in the pound. The money would be remitted to the Treasury and Scotland would continue to receive a block grant negotiated each year in the public spending round.
The parliament would have a chief minister, who would allocate ministerial portfolios.
In elections, Scottish voters would have two votes - a first-past-the- post vote for 73 constituency MPs and a second vote to select 56 additional members by party to help ensure that the final make-up of the parliament reflected parties' share of the vote.
Parliaments would sit for four-year fixed terms and members could not sit as Westminster or Euro-MPs or councillors.
The main areas left to Westminster would be defence, foreign affairs, immigration, social security and central economic and tax policy.