Nicola Sturgeon will be handed powers to significantly reshape the welfare state in Scotland within weeks.

The UK Government is to fast-track moves that will allow the First Minister to create new benefits payments.

The changes could be in place by the time that Holyrood returns from its summer break in September.

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The SNP has said that it plans to use the range of new welfare powers destined for Holyrood to create a more compassionate system.

But Ms Sturgeon will not yet be able to alter existing benefits.

Sources said that the complexity of the UK’s social security operation mean that that would take longer to devolve.

Around 50 Department for Work and Pensions (DWP) staff are currently working on the devolution programme.

A Whitehall source said: “Some of the powers can be handed over quickly.”

The changes were agreed by the Smith Commission on extra devolution.

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The cross-party group was set up in the wake of 2014's independence referendum.

The resultant Scotland Act will being in sweeping tax and welfare reforms set to reshape the political settlement between Edinburgh and London.

Conservative ministers are keen to give the SNP responsibility to raise part of the money they spend and be forced to take tough decisions on issues such as welfare.

MSPs are also due to be be given powers to vary elements of the new Universal Credit benefit, end the spare room subsidy, or "bedroom tax", increase Carers' Allowance.

Scottish Secretary David Mundell has pushed for powers to be transferred as quickly as possible.

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He said earlier this year: “If the Scottish Government wanted to treble Jobseeker's Allowance, they could.”

A Conservative source said that the powers were "really significant ... so the Scottish Parliament can begin the process of creating its own welfare system within Scotland and within the range of powers provided by the Smith Commission".

The UK Government will make the order in Parliament on Thursday.

The Scotland Bill also included plans to give MSPs control over all income rates and bands from April next year.

Overall, the Scotland Bill will devolve almost full control over income tax and a £2.5 billion welfare budget to Holyrood.

But the SNP has repeatedly said that the plans fall short of delivering the Smith report in full.

The party has said that decisions on 85 per cent of welfare spending will continue to be made in London.