Nicola Sturgeon has executed the bloodiest and most sweeping reshuffle of devolution by changing half her cabinet, including the beleaguered Health Secretary Shona Robison.

The dramatic clear-out saw the departure of three cabinet secretaries and three ministers, and the promotion of five new faces to an expanded top tier of government.

The First Minister said the changes, which are due to continue today with the appointment of nine new ministers, would bring fresh blood to the 11-year-old administration.

Ms Sturgeon increased the cabinet from 10 to 12 positions to reflect the bigger government workload arising from Brexit, and to ensure the smooth running of a new £300m devolved social security system, which is seen as a crucial test of government competence.

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She said: “People already have high trust in the Scottish Government to look after their interests, and I am determined this new, refreshed Cabinet will continue to repay that trust.”

The opposition parties said the new faces would mean little unless they were accompanied by new policies and priorities from the Government.

Given Ms Sturgeon’s previous aversion to reshuffles, the new line-up is likely to be the one she keeps until the next Holyrood election in 2021, when she is hoping to win a new mandate for an independence referendum.

It was the biggest mid-term shake-up since Labour's Jack McConnell became First Minister in 2001 and sacked four ministers to put his own stamp on the office.

Mr Robison and Communities Secretary Angela Constance, who had been tipped for the sack, both handed in resignations before the reshuffle began.

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Despite being Ms Sturgeon’s closest political ally, Ms Robison had been left vulnerable by mounting problems in the NHS, including a raft of missed treatment targets.

In her resignation letter, she said she had also suffered a challenging last year in her personal life, with the loss of both parents and a cancer scare.

Economy Secretary Keith Brown, whose tenure saw official growth forecasts downgraded to below 1 per cent for the next five years, is now to focus on party business.

Elected deputy leader earlier this month, he had hoped to combine the role with a cabinet position, but now gets a £42,000 pay cut to become the SNP’s “standing campaign director”.

The SNP said his job would involve policy development, preparing the party for the next general and Holyrood elections, and promoting independence.

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After an afternoon of comings and goings at Bute House, Ms Sturgeon announced the new cabinet members would be Humza Yousaf at Justice, Jeane Freeman at Health, Shirley Anne-Somerville at Social Security and Older People, and Aileen Campbell at Communities.

Brexit minister Michael Russell, a previous Education Secretary, returns to the cabinet as Secretary for Government Business and Constitutional Relations.

Michael Matheson moves sideways from Justice to a new Transport and Infrastructure role.

Despite shelving the government’s flagship Education Bill yesterday, John Swinney remains at Education and Skills, while Roseanna Cunningham and Fiona Hyslop stay at Environment and External Relations respectively, and Derek Mackay has the economy added to his finance brief.

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Three ministers - Dr Alasdair Allan, Maureen Watt and Annabelle Ewing - were sacked, three remained remained in post and two were moved to new posts.

The changes are expected to cost taxpayers an extra £100,000 a year in salaries.

The six departing ministers will also share around £55,000 in compensation for the loss of office.

Ms Sturgeon said the overhaul brought “fresh talent to the Scottish Government”.

She said: “With the impact of Brexit on our economy and wider society, it is right that the issues it presents are fully reflected at Cabinet level, while the delivery of a new Scottish social security system also requires a voice at the Cabinet table.

“Those appointments, together with the reshaped portfolios, mean that people can have confidence that the Scottish Government will continue to deliver for people, public services and communities the length and breadth of the country.”

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She thanked Mr Brown, Ms Robison and Ms Constance for their “hard work, commitment and dedication” and said each had “achievements that they can be proud of”.

She promised a “fully refreshed junior ministerial team” with “a wealth of new talent”.

Tory MSP Jackson Carlaw said “There may have been a few ministerial changes. But this is a government that is tired, completely out of ideas and all over the place on key issues.”