SNP MPs at Westminster could try to change the new Scotland Bill to make Holyrood responsible for raising all the money it spends.

Deputy First Minister John Swinney said "of course" his party could table amendments for full fiscal autonomy as the legislation makes its way through Westminster.

He spoke out after new Conservative Scottish Secretary David Mundell pledged the UK Government would move "very quickly" to implement the Bill, which is published today.

Mr Mundell insisted the legislation would implement the recommendations of the Smith Commission - the cross party body set up to examine the issue of giving Scotland more powers in the wake of last year's independence referendum.

Scotland's only Conservative MP told BBC Radio Scotland: "The Government position is to implement the Smith Commission.

"If others have proposals they need to bring them forward, but they need to bring them forward in an evidenced way, they need to show why these additional powers would be required, what benefits they would bring to Scotland, how they would affect the United Kingdom as a whole."

Mr Mundell told the Good Morning Scotland programme: "The message I got during the general election was the SNP MPs were going to be a voice for Scotland, they were coming to the Westminster parliament to ensure we delivered on our commitments to bring forward extra powers.

"We are delivering, this is one of the first bills that is coming forward, it's going to be a very significant part of Parliament's deliberations over the next few weeks.

"It meets the Smith Commission criteria, it's going to make very, very substantial changes to the Scottish Parliament, to the ability of the Parliament and the Government to shape policies within Scotland and we're getting on with it."

The Scotland Bill will make Holyrood responsible for raising about 40% of taxes, according to the UK Government, with powers to set the thresholds and rates of income tax included in the legislation - and with all the money this brings in staying north of the border.

It also proposes giving Holyrood some money from VAT revenues, devolving responsibility for air passenger duty and giving MSPs about £2.5 billion worth of new powers over welfare, according to Westminster.

Mr Mundell said: "I'm very keen that we then get on to implement it, so the Scottish Parliament has these powers, the Scottish Government can then take the decisions they say they need to do to make changes in Scotland in relation to the economy, welfare, and other matters. That's my priority."

But Mr Swinney said the draft clauses that had been published for the Bill had "failed utterly to put in place the legislative changes to implement the Smith Commission report".

The Deputy First Minister, also speaking on BBC Radio Scotland, said: "The Smith Commission has got to be converted in spirit and in substance into legislation - that is not what was proposed in January and that is the big test for Mr Mundell and the Conservative Government."

When asked if the SNP would try to change the Bill to introduce full fiscal autonomy for Scotland, Mr Swinney said "of course there could be" such an amendment

He added: "There could be other amendments to try to strengthen the powers."

The Deputy First Minister said: "The definition of full fiscal responsibility is crystal clear, it's giving the Scottish Parliament power to ensure we can create better economic opportunities and better economic prospects for Scotland by ensuring we have got control of a range of different areas, whether it is business taxation, or the setting of the minimum wage, or about National Insurance, or a variety of other policies and powers that would enable us to strengthen the economic performance of Scotland and create the employment and the opportunities people in our country are looking for."

He argued that while the powers already proposed were "welcome" there is still a "necessity for the UK Government to recognise that if the (Scottish) Parliament is to be equipped with all the powers it requires, it needs to have a comprehensive range of economic powers into the bargain, and we will argue for that".