BORIS Johnson is the “voice of the majority of the Scottish people” who rejected independence, Downing Street has claimed.

The comments came amid turmoil in the No 10 Union unit, with the group's only Scot, former Ochil and South Perthshire MP Luke Graham, ousted from his leadership role after a "brutal" dispute over indyref2.

The Prime Minister’s official spokesman confirmed Graham has “left his No 10 position” just two days after Johnson’s press secretary Allegra Stratton said he was a “very valued member of staff”.

“The No 10 Union unit will continue to support the Prime Minister in his capacity as the Minister for the Union,” the spokesman said.

“We don’t comment on details of personnel matters but the Union is an incredibly important focus of the Prime Minister and the No 10 Union unit will continue to support him on that.”

READ MORE: Only Scot on Boris Johnson's Union Unit is sacked over indyref2 dispute

The Financial Times reported that Graham clashed with Oliver Lewis – a veteran of the Vote Leave Brexit campaign – on Friday, the day after the Prime Minister returned from a visit to Scotland.

Lewis, known in No 10 as "Sonic", is to take over what Government officials described as a “beefed-up union unit”.

Lewis was a key Tory figure in last year’s Brexit trade negotiations and is believed by the Tories to have campaigning credentials, but he is not known for any particular expertise in Scottish politics. He threatened to resign over the departure of Dominic Cummings in November, but was persuaded by the Prime Minister to stay in Downing Street.

The SNP said the move was a “Vote Leave takeover” which would drive up support for independence.

READ MORE: The Union Unit has shown itself to be useless – but beware its dirty tricks

Asked whether No 10 was now on a war footing ahead of a battle with the SNP, a No 10 spokesman said: “As the Prime Minister has said himself, he thinks all parts of the Union are stronger together and he will be and continue to be the voice of the majority of the Scottish people who voted to keep the UK together.

“He will always stand against those trying to separate the UK which is why it remains an important focus.”

Lewis's colleagues said he wanted “a clean slate” and to build a new team. “Oliver is good at this stuff — he knows this can’t just be about brute economics,” said one colleague. “It’s about passion, identity and about promoting the idea that you can be proud to be Scottish and British.”

Graham's departure has fuelled claims that Johnson does not understand the situation in Scotland. But allies said were still Scottish people involved in work on the Union, sich as Chancellor of the Duchy of Lancaster Michael Gove.

The SNP’s deputy Westminster leader Kirsten Oswald said: “The Vote Leave takeover of Boris Johnson’s taxpayer-funded anti-independence campaign has spectacularly backfired – and will drive up support for independence even further.

“By installing Dominic Cummings’ Brexit apprentice as head of the so-called ‘Union unit’, the Prime Minister is demonstrating, yet again, that he is completely clueless about Scotland.”

Some insiders say Graham, who will now move to Edinburgh to work with the Scottish Tories, did not have the authority to do his job. "There was a lack of faith in letting him do what he needed to do. A lot of his efforts were frustrated by other people in the building," one said.

READ MORE: Boris Johnson draws up five-step plan to 'save the Union' from collapse

Johnson has repeatedly insisted that Scots don't want a new vote on independence, despite 20 polls in a row putting Yes in the lead. Lewis’s role will be central to Number 10’s efforts to counter the SNP.

Graham was apparently unhappy with both his role and the Tories' strategy for the Union. “There was a lack of faith in letting him do what he needed to do. A lot of his efforts were frustrated by other people in the building,” one said.

A Scottish Tory added: “Luke was the only one who gets Scotland in there, it’s a big shame he’s gone and speaks to their total lack of a strategy on how to deal with the SNP.”