Rachel Reeves 'let everyone know who's boss' and looked like 'an angry teacher in school assembly' in her first major speech as Chancellor, a body language expert has said.
Speaking at the Treasury for the first time, Ms Reeves vowed to make a dramatic overhaul of the 'timid' planning system to stop housing developments being blocked.
She also spoke about stripping local people of powers to object to onshore windfarms as decisions are to be taken at national level, and said she wanted to unblock the process for other major projects.
Analysing the inaugural speech of Britain's first female Chancellor, body language expert Judi James told MailOnline that Ms Reeves delivered a performance of 'charm mixed with the tone of an authoritative and rather angry head teacher'.
She added that Ms Reeves 'tough' tonal style was also 'very on-brand' with Sir Keir Starmer's first speech as PM, with her delivery 'designed to give the impression of decisiveness'.
Speaking at the Treasury for the first time, Rachel Reeves vowed to make a dramatic overhaul of the 'timid' planning system to stop housing developments being blocked
Analysing the historic speech of the first female Chancellor, body language expert Judi James told MailOnline that Ms Reeves delivered a performance of 'charm mixed with the tone of an authoritative and rather angry head teacher'
She said: 'Placed under intense scrutiny in her new role as a global financial power-broker, Reeves delivers a body language performance of charm mixed with the tone of an authoritative and rather angry head teacher addressing the school during assembly.
'Her tonal approach is very on-brand with Starmer's first speech as PM. Their leadership style during their speeches looks firm to the point of strict, as though toughness has been a deliberate brand decision.'
Ms Reeves set the stage for Labour's big push on planning by admitting that the public finances are so stretched that boosting growth is the 'only route to improving the prosperity of our country'.
According to Ms James, the Chancellor's repeated use of the word 'I' in the speech helped her 'grab the helm of the Treasury and let everyone know who is boss'.
She said: 'Reeves grabs the helm of the Treasury and lets everyone know who is boss, with the repeated use of the word 'I' starting off some 'critical parent'-style statements like "I made clear", "I'm not willing to accept" and "I will not be playing games..." and "I will not hesitate to act" with the word 'I' delivered in tonal italics.
'Her delivery looks designed to give the impression of decisiveness. Describing "The only route" to financial stability she performs a micro head-cock as though daring anyone to challenge her.
'Her "I have repeatedly warned..." comes with a grim eye expression as her smile drops and she launches into her tough talk, and when she seems to want to set out her strength in the new role there is a micro-snarl of the top lip and later a micro-sneer as her upper cheeks lift as she informs her audience "I will not shrink....'
Ms James also compares Ms Reeves performance to former Prime Minister Margaret Thatcher as she 'combines this tough act with moments of disarming charm'.
She continued: 'Telling the world "Britain is a place to do business" Reeves performs a prim, firm pursing of the lips followed by an exaggerated toss of the head in a look of defiance while her eyelids flutter to suggest a glint of defiant anger.
'Like Thatcher back in the day, though, Reeves combines this tough act with moments of disarming charm. Like Thatcher her smile flashes on regularly, especially at the start, and then when she asks each journalist for their question.
'When she is called 'chancellor' by one journalist her dimpled smile is a beam of what looks like delight to hear herself called by her new title, suggesting some intense celebrations in private, behind closed doors.'
Chancellor Rachel Reeves will put her faith in a dramatic overhaul of the planning system to boost economic growth
A slew of Cabinet ministers were on hand at the Treasury to watch Ms Reeves' speech today
Ms Reeves is embraced by business secretary Jon Reynolds after her speech today
Ms Reeves was appointed as Britain's first female Chancellor on Friday, and warned that there was 'not much money around'.
However, left-wing MPs and union leaders are already pushing for Sir Keir and Ms Reeves to turn on the spending taps.
Unite boss Sharon Graham said there was scope for the Government to borrow tens of billions of pounds to 'invest' in the economy and public services.
She urged Ms Reeves to scrap Labour's tight fiscal rules and pour billions into Britain's 'crumbling public services'.
'We are going to have to borrow to invest,' she told the BBC's Sunday with Laura Kuenssberg. 'We have not got time to wait for growth.
'People are literally hurting out there and we are going to have to borrow to invest – our crumbling public services need money.'
However, Ms Reeves insisted today that she will not 'throw caution to the winds' and ditch fiscal rules to borrow more.
Touring broadcast studios ahead of Ms Reeves' appearance this morning, Treasury chief secretary Darren Jones said that stimulating 'strength and growth' in the economy is Labour 's 'first and most important mission'.
He tried to play down concerns that local communities will be 'excluded' from decisions on housing projects, saying the idea was just to remove 'inertia'.
Greater Manchester mayor Andy Burnham has also called for a 'decisive break with austerity'.
Labour's decision to target the planning system immediately is likely to bring it into conflict with both countryside campaigners and those communities that feel they are already at the limit of development their area can take.
It could also trigger a backlash from some of its own MPs who represent a swathe of constituencies across southern England where planning reform has been resisted for years.
During the election campaign, one Labour official said the party was prepared to 'flatten the whole green belt'. This was denied by Labour.
Ben Houchen, Tory mayor of Tees Valley, said promising rapid growth on the back of planning reform could become 'a noose around the Labour Party's neck'.
He added: 'How keen are the Labour Government to tinker with environmental regulations which is one of the largest delays in the planning system?'
Sir Keir yesterday began a whistle-stop tour of the UK with a visit to Scotland, where he promised an 'immediate reset' of relations with the devolved administrations.
Tomorrow he will travel to the Nato summit in Washington where he will seek to reassure leaders that his Government can be trusted on defence despite ditching Rishi Sunak's pledge to raise military spending to 2.5 per cent of GDP by the end of the decade.
