Plans for a radical transfer of power from Westminster to Holyrood have been signed, sealed and delivered, Ed Miliband insisted.

The Labour leader visited Glasgow the day after a new set of proposals on extending devolution was unveiled.

He pledged to put these into law in his first programme of government if he becomes prime minister next May.

Mr Miliband hailed the package, which has been put forward by the Smith Commission on devolution, as a "radical transfer of powers that puts the Scottish Parliament as one of the most powerful parliaments of its kind in the world".

He told party activists: "Elect a Labour government in May and we will implement the Smith Commission in our first Queen's Speech. This is my promise to the people of Scotland."

Mr Miliband said Scots had shown in the referendum campaign that they wanted greater control over decisions north of the border and stronger powers for the Scottish Parliament.

He stated: "We have listened. We have learned. And we have changed.

"A vow was signed during the referendum campaign.

"It was sealed by the votes of the Scottish people.

"It was delivered by the Smith Commission."

Mr Miliband insisted: "It has been signed. It has been sealed. It has been delivered."

The Smith Commission had been set up by the UK Government immediately after September's referendum - in which 45% of voters backed independence.

Just days before the historic vote, Mr Miliband, Conservative leader David Cameron and Liberal Democrat leader Nick Clegg jointly vowed Scotland would get substantial new powers if it voted to stay in the UK.

Representatives from the five parties at Holyrood - the SNP, Labour, the Tories, Liberal Democrats and the Greens - worked together to produce the report, which will now form the basis for draft legislation to be published in January.

The leaders of the Westminster parties have already pledged that this will be put into law regardless of the outcome of next May's general election.

The commission called for the Scottish Parliament to get new powers to set income tax rates and bands, with all the cash raised in Scotland to go to Holyrood and not Westminster.

All other aspects of income tax will remain reserved, including the threshold at which people have to pay the charge.

Scotland could be granted control over certain benefits - including attendance allowance, carer's allowance, disability living allowance, and the personal independence payment which will replace it - but other welfare payments and power over the state pension will remain with the UK Government.

While the commission backed the devolution of air passenger duty, a range of other taxes, including corporation tax and inheritance tax, will continue to be decided in London.

New Scottish First Minister Nicola Sturgeon has already insisted that the recommendations do not go far enough.

''We don't think it lives up to the rhetoric that was used by the Westminster parties in the run-up to the referendum," she said yesterday.

But Mr Miliband said: "It's the first time anyone has tried to dump a report they signed up to within less than 24 hours."

He stated: "I think the SNP's position is an odd position and I think it's important that we say 'we have delivered', after all this is a more radical position than any of the parties were proposing at the time of the referendum.

"Now we have to get on with the argument of how those powers are going to be used."

The SNP has seen its support rise in the wake of the decision to stay in the UK, with membership rising to more than 92,000 and opinion polls putting the nationalists ahead of Labour in both Holyrood and Westminster voting intentions.

Meanwhile, Labour is hunting for a new leader in Scotland after Johann Lamont resigned suddenly, accusing party colleagues in Westminster of treating Scotland like a "branch office".

Mr Miliband said: "We're going to be electing a new leader in Scotland shortly and they will take forward the argument and the fight with the SNP, and I will be part of that.

"I think the most important argument over the next five months is what kind of government people want after the general election because there are only two outcomes - you will either have a Labour government or a Conservative government.

"We have a fight on to show that we are going to make a difference to Scotland and how we are going to make a difference to Scotland.

"Yesterday was a really important step forward in showing the Scottish people that we have delivered on what we promised.

"I feel a great sense of what we can achieve because we are delivering on powers and we have an agenda on social justice that beats the SNP's by a long distance."

Mr Miliband said some people would ask if the Smith Commission recommendations provided "a path to the break-up of the country".

But he stated: "I do not believe it does."

Instead, he said, the proposals were about "bringing power closer to people while maintaining the benefits of the UK".

He added: "Significantly-enhanced powers for the Scottish Parliament but with the continued pooling and sharing of resources across the United Kingdom.

"We will all continue to pay National Insurance together, so we can have a decent state pension across the United Kingdom.

"We will continue together to support working people and families with tax credits so that we can make work pay across the United Kingdom.

"We will continue to tackle child poverty, with child benefit across the United Kingdom.

"We will continue to share resources and support each other.

"The Smith Commission represents a way forward for stronger powers for the Scottish Parliament."

The Labour leader insisted that the measures being put forward represented a "huge change in the way the United Kingdom will be governed".

He said: "We have been, for so long, a centralised country. With power hoarded at Westminster."

Labour had "started to break the centralisation of our country" with the establishment of the Scottish Parliament in 1999.

But Mr Miliband stressed that "devolution is not just for one part of the United Kingdom" as he vowed: "We will bring power closer to people across the whole country.

"Because devolution will not stop at the Scottish border."

While he said devolution would not be "precisely the same in every part of Britain", he argued that changes must be made on a UK-wide basis.

To achieve that, the Labour leader said: "In Wales, we will put devolution on a new legal foundation.

"We will make changes in England too. For far too long, England has been one of the most centralised nations in the world.

"We are determined to change that by devolving real powers and real responsibilities to the cities and counties of England.

"So that, just as happens in Scotland, local people and local businesses can come together to create new jobs, better transport links, more skills and opportunities for the next generation. That is what will be in our manifesto."

The SNP said that the Smith Commission's proposals had left a number of organisations in civic Scotland "disappointed".

SNP MSP Linda Fabiani represented the party on the commission, along with Deputy First Minister John Swinney.

Nationalists have highlighted the response from groups such as the Scottish Trades Union Congress, the Child Poverty Action Group, the National Union of Students, One Parent Families Scotland, Engender Scotland, the Scottish Council for Voluntary Organisations, the Public and Commercial Services Union, the Equality Network, Inclusion Scotland and the Campaign for Scottish Home Rule, in support of their stance that the recommendations could have gone further

Ms Fabiani said: "Civic Scotland's disappointment with the Smith Commission proposals is clear - with many organisations feeling an opportunity to tackle poverty and inequality has been missed.

"In their submissions to the Smith Commission, 65 organisations called for welfare devolution, a number of organisations called for devolution of the minimum wage and many called for powers over equality legislation. None of these powers have been forthcoming.

"Westminster decisions on welfare are continuing to devastate communities across Scotland, with food bank use rocketing 400% in the past year. And in-work poverty is also on the rise as the UK minimum wage fails to keep up with the cost of living.

"With 70% of our taxes and 85% of welfare staying at Westminster, the Scottish Parliament's hands will continue to be tied as consecutive Westminster governments make the wrong choices for Scotland."

She added: "The SNP will always welcome new powers for Scotland - and we have been clear that in government we will use them in the best interests of the Scottish people.

"However, the fact is that the proposals do not meet the aspirations of the Scottish people and civic Scotland.

"The proposals put forward today make it crystal clear that the Westminster parties are not prepared to give Scotland the extensive powers needed to build a prosperous and fairer country. Next May, the Scottish people have the opportunity to make their voice heard and let the Westminster establishment parties know that they want more powers to enable Scotland to tackle poverty and inequality. We look forward to their verdict."

Mr Miliband underlined his plans for greater devolution to the English regions, including transferring control over £30 billion worth of funding.

During a visit to the Nissan car plant in Sunderland, the Labour leader said: "The Smith Commission has recognised the need to go further in Scotland.

"But Labour recognises that devolution does not and must not stop at the Scottish border. It must represent a change, a new principle, determining how we are governed throughout the United Kingdom, bringing power closer to people across the whole country.

"For far too long, England has been one of the most centralised nations in the world, choking off the energy and the initiative of the great towns and cities that once powered the industrial revolution: Leeds, Manchester, Newcastle, Sunderland and many others.

"We are determined to change that by devolving real powers and real responsibilities to the cities and counties of England, so that just as happens in Scotland, local people and local businesses can come together to create new jobs, better transport links, more skills and opportunities for the next generation."